This document discusses bolted connections used in structural engineering. It begins by explaining why connection failures should be avoided, as they can lead to catastrophic structural failures. It then classifies bolted connections based on their method of fastening, rigidity, joint resistance, fabrication location, joint location, connection geometry, and type of force transferred. It describes different types of bolts and bolt tightening techniques used for friction grip connections. It discusses advantages and drawbacks of bolted connections compared to riveted or welded connections. The document provides detailed information on design and behavior of various bolted connections.
This presentation summarizes different types of bolted connections. It discusses bearing bolts, which can be unfinished or finished. Unfinished bolts have rough shanks while finished bolts have circular shanks from turning. It also defines terminology used in bolted connections like pitch, gauge distance, and edge distance. Finally, it discusses grade classifications for bolts based on their strength and specifies requirements for bolted connections according to Indian codes and standards, distinguishing between lap joints and butt joints.
This document discusses types of bolt connections based on arrangement of bolts and plates, mode of load transmission, and nature and location of load. There are two main types of joints subjected to axial loads: lap joints and butt joints. Butt joints are preferable to lap joints because the load is split between members, eliminating eccentricity and bending. Bolt connections can fail due to shear, bearing, or tension failures of bolts or plates. The design strength of bolts is governed by their strength in shear, bearing, or tension with safety factors applied.
This document discusses riveted connections in steel structures. It describes the different types of rivets, including their shape and method of installation. Some key types are snap headed rivets, pan headed rivets, and flat counter sunk rivets. It also outlines the advantages and disadvantages of riveted connections. Advantages include ease of installation without electricity, while disadvantages include noise and required skilled labor. The document further explains different riveted joint configurations, including lap joints and butt joints, providing examples of single and double riveted versions of each. Finally, it briefly outlines potential failure modes of riveted connections, such as shear failure of rivets or plates, and bearing failure of plates or
Connections are critical components that join structural elements to transfer forces safely. Steel connections influence construction costs and failures often originate from connections. Common steel connections include bolted, welded, and riveted joints. Bolted connections can be bearing type or friction grip bolts. Welded joints include fillet and butt welds. Connections must be designed for the expected loads, with shear connections allowing rotation and moment connections resisting it. Proper connection design is important for structural integrity and economy.
Design of steel structure as per is 800(2007)ahsanrabbani
It does not offer resistance against rotation and also termed as a hinged or pinned connections.
It transfers only axial or shear forces and it is not designed for moment
It is generally connected by single bolt/rivet and therefore full rotation is allowed
information on types of beams, different methods to calculate beam stress, design for shear, analysis for SRB flexure, design for flexure, Design procedure for doubly reinforced beam,
The document discusses bolted connections and provides specifications for bolt hole sizes, pitch, and spacing in bolted connections according to IS 800-2007. It covers various types of bolted joints including lap joints, butt joints, and their modes of failure. High strength friction grip bolts are described which provide rigid connections through clamping action and prevent slippage. The advantages of HSFG bolts include their ability to transmit load through friction eliminating stress concentrations in holes, while their drawbacks include higher cost and fabrication efforts compared to normal bolts.
Prestressed concrete is concrete that is placed under compression using tensioned steel strands, cables, or bars. This is done through either pre-tensioning or post-tensioning. In pre-tensioning, the steel components are tensioned before the concrete is poured, while in post-tensioning, the steel components are tensioned after the concrete has hardened. Prestressed concrete provides benefits over reinforced concrete like lower construction costs, thinner structural elements, and longer spans between supports.
This presentation summarizes different types of bolted connections. It discusses bearing bolts, which can be unfinished or finished. Unfinished bolts have rough shanks while finished bolts have circular shanks from turning. It also defines terminology used in bolted connections like pitch, gauge distance, and edge distance. Finally, it discusses grade classifications for bolts based on their strength and specifies requirements for bolted connections according to Indian codes and standards, distinguishing between lap joints and butt joints.
This document discusses types of bolt connections based on arrangement of bolts and plates, mode of load transmission, and nature and location of load. There are two main types of joints subjected to axial loads: lap joints and butt joints. Butt joints are preferable to lap joints because the load is split between members, eliminating eccentricity and bending. Bolt connections can fail due to shear, bearing, or tension failures of bolts or plates. The design strength of bolts is governed by their strength in shear, bearing, or tension with safety factors applied.
This document discusses riveted connections in steel structures. It describes the different types of rivets, including their shape and method of installation. Some key types are snap headed rivets, pan headed rivets, and flat counter sunk rivets. It also outlines the advantages and disadvantages of riveted connections. Advantages include ease of installation without electricity, while disadvantages include noise and required skilled labor. The document further explains different riveted joint configurations, including lap joints and butt joints, providing examples of single and double riveted versions of each. Finally, it briefly outlines potential failure modes of riveted connections, such as shear failure of rivets or plates, and bearing failure of plates or
Connections are critical components that join structural elements to transfer forces safely. Steel connections influence construction costs and failures often originate from connections. Common steel connections include bolted, welded, and riveted joints. Bolted connections can be bearing type or friction grip bolts. Welded joints include fillet and butt welds. Connections must be designed for the expected loads, with shear connections allowing rotation and moment connections resisting it. Proper connection design is important for structural integrity and economy.
Design of steel structure as per is 800(2007)ahsanrabbani
It does not offer resistance against rotation and also termed as a hinged or pinned connections.
It transfers only axial or shear forces and it is not designed for moment
It is generally connected by single bolt/rivet and therefore full rotation is allowed
information on types of beams, different methods to calculate beam stress, design for shear, analysis for SRB flexure, design for flexure, Design procedure for doubly reinforced beam,
The document discusses bolted connections and provides specifications for bolt hole sizes, pitch, and spacing in bolted connections according to IS 800-2007. It covers various types of bolted joints including lap joints, butt joints, and their modes of failure. High strength friction grip bolts are described which provide rigid connections through clamping action and prevent slippage. The advantages of HSFG bolts include their ability to transmit load through friction eliminating stress concentrations in holes, while their drawbacks include higher cost and fabrication efforts compared to normal bolts.
Prestressed concrete is concrete that is placed under compression using tensioned steel strands, cables, or bars. This is done through either pre-tensioning or post-tensioning. In pre-tensioning, the steel components are tensioned before the concrete is poured, while in post-tensioning, the steel components are tensioned after the concrete has hardened. Prestressed concrete provides benefits over reinforced concrete like lower construction costs, thinner structural elements, and longer spans between supports.
Prestressed concrete combines high-strength concrete and high-strength steel in an active manner by tensioning steel tendons and holding them against the concrete, putting it into compression. This transforms concrete from a brittle to a more elastic material. It allows for optimal use of each material's properties and better behavior under loads. Prestressed concrete was pioneered in the 1930s and its use has expanded, finding applications in bridges and other structures. Common methods are pretensioning and post-tensioning, using various tendon types, with bonded or unbonded configurations. Tensioning is done using mechanical, hydraulic, electrical or chemical devices.
This document provides guidance on the design of lacing and battens for built-up compression members. It discusses the key design considerations and calculations for both single and double lacing systems, including the angle of inclination, slenderness ratio, effective lacing length, bar width and thickness. Similar guidelines are given for battens, covering spacing, thickness, effective depth, transverse shear and overlap. The document also includes an example problem on designing a slab foundation for a column with given load and material properties.
This document provides an overview of the design of steel beams. It discusses various beam types and sections, loads on beams, design considerations for restrained and unrestrained beams. For restrained beams, it covers lateral restraint requirements, section classification, shear capacity, moment capacity under low and high shear, web bearing, buckling, and deflection checks. For unrestrained beams, it discusses lateral torsional buckling, moment and buckling resistance checks. Design procedures and equations for determining effective properties and capacities are also presented.
This document summarizes the key aspects of flat slab construction and design according to Indian code IS 456-2000. It defines flat slabs as slabs that are directly supported by columns without beams, and describes four common types based on whether drops and column heads are used. The main topics covered include guidelines for proportioning slabs and drops, methods for determining bending moments and shear forces, requirements for slab reinforcement, and an example problem demonstrating the design of an interior flat slab panel.
In science, buckling is a mathematical instability, leading to a failure mode.
Buckling is characterized by a sudden sideways failure of a structural member subjected to high compressive stress, where the compressive stress at the point of failure is less than the ultimate compressive stress that the material is capable of withstanding
This document provides information on industrial buildings, including their components and factors to consider in design. Key points include:
- Industrial buildings are used for manufacturing and storage by industries and include steel plants, warehouses, and factories.
- Site selection considers access, raw materials, utilities, land characteristics, and transportation.
- Major components include the roof, trusses, purlins, girts, bracing, and foundations.
- Design considerations cover roofing/wall materials, bay widths, structural framing, truss configurations, and bracing to resist lateral loads.
The document discusses the design of steel structures according to BS 5950. It provides definitions for key terms related to steel structural elements and their design. These include beams, columns, connections, buckling resistance, capacity, and more. It then discusses the design process and different types of structural forms like tension members, compression members, beams, trusses, and frames. The properties of structural steel and stress-strain behavior are also covered. Methods for designing tension members, including consideration of cross-sectional area and end connections, are outlined.
This document discusses different types of columns used in construction. It defines a column as a structural member subjected to compressive axial loads. Columns are classified as long, short, or intermediate based on their length-to-minimum radius of gyration ratio. Long columns have a ratio greater than 50, short columns less than 15-50, and intermediate between 30-100. The document provides examples of column types and discusses effective length, radius of gyration, buckling load, and Euler's formula for calculating crippling load.
A system of prestressing involves tensioning tendons and securing them firmly to concrete. There are two main types: pre-tensioning and post-tensioning. Pre-tensioning involves pulling tendons tight between anchored abutments before concrete is poured. The Hoyer or long-line pre-tensioning system uses bulkheads to stretch wires over which molds are placed for concrete pouring. The Freyssinet system was the first post-tensioning method, using a cable of high-strength wires grouted into a duct within the concrete beam. Wires are anchored using conical plugs pushed into holes in concrete cylinders after jacking. The Magnel Blaton system tensions wires in pairs using sandwich plates
The document discusses limit state design of reinforced concrete structures. It introduces limit states as conditions where the structure becomes unfit for use, including limit states of strength and serviceability. Limit state design involves characterizing loads and resistances as random variables and using partial safety factors on loads and resistances to achieve a target reliability. The document outlines the general principles of limit state design according to Indian Standard code IS 800, including defining actions, factors governing strength limits, and serviceability limits related to deflection, vibration and durability.
This document provides an overview of the design of compression members (columns) in reinforced concrete structures. It discusses various types of columns based on reinforcement, loading conditions, and slenderness ratio. It describes the classification of columns as short or slender. The document also covers effective length, braced vs unbraced columns, codal provisions for reinforcement, and functions of longitudinal and transverse reinforcement. Key points include types of column reinforcement, minimum reinforcement requirements, cover requirements, and assumptions for the limit state of collapse under compression.
This document discusses post-tensioning devices and systems. Post-tensioning involves applying tension to tendons placed in ducts within hardened concrete. There are two main types: bonded uses grout in the ducts while unbonded does not. Key devices include ducts, anchoring devices, jacks and optional couplers and grouting equipment. Common anchoring principles are wedge action, direct bearing and looping wires. More than 64 post-tensioning systems have been patented worldwide with the Freyssinet system most common in India.
Post-tensioning is an effective alternative for earthquake-prone regions and dense populations in India. It has advantages over ordinary reinforced concrete like higher seismic resilience, less concrete usage, stiffer foundations, and faster construction. Post-tensioning involves threading steel tendons through ducts and tensioning them after concrete pouring. It provides better crack control, economy, quality, and efficiency. While widely used in other countries, post-tensioning is not yet common in India but has applications in slabs, buildings, and foundations.
The document discusses the design of footings for structures. It begins by explaining that footings are needed to transfer structural loads from members made of materials like steel and concrete to the underlying soil. It then describes different types of shallow and deep foundations, including spread, strap, combined, and raft footings. The document provides details on designing isolated and combined footings to resist vertical loads and moments based on provisions in IS 456. It also discusses wall footings and combined footings that support multiple columns. In summary, the document covers the purpose of footings, various footing types, and design of isolated and combined footings.
The document discusses different methods of post-tensioning concrete structures. It describes the Freyssinet system as the first introduced method using steel wires grouped into cables with a helical spring. The Magnel Blaton system stresses wires two at a time using sandwich plates and wedges. The Gifford Udall system uses single wires stressed independently with double-acting jacks and tube or plate anchorages. The Lee McCall system prestresses steel bars using threaded bars tightened with nuts against bearing plates.
This document discusses riveted connections and their design. It covers the different types of riveted joints like lap joints and butt joints. It provides specifications for riveted connections like the gross diameter of rivets, gauge, pitch and edge distance. It also discusses the types of failures in riveted connections and how to calculate the strength of riveted joints based on the strength of rivets in shear and bearing and the strength of plates in tension. The efficiency of riveted joints is defined. Examples of calculating rivet values are also provided.
This document discusses the design of compression members subjected to axial load and biaxial bending. It introduces the concept of biaxial eccentricities and explains that columns should be designed considering possible eccentricities in two axes. The document outlines the method suggested by IS 456-2000, which is based on Breslar's load contour approach. It relates the parameter αn to the ratio of Pu/Puz. Finally, it provides a step-by-step process for designing the column section, which involves determining uniaxial moment capacities, computing permissible moment values from charts, and revising the section if needed. It also briefly mentions the simplified method according to BS8110.
This document discusses different methods of prestressing concrete, including pretensioning and post-tensioning. Pretensioning involves stressing steel tendons before placing concrete around them, while post-tensioning involves stressing tendons after the concrete has cured using hydraulic jacks. Post-tensioning allows for longer spans, thinner slabs, and more architectural freedom compared to conventional reinforced concrete or pretensioned concrete. Common applications of post-tensioning include parking structures, bridges, and building floors and roofs.
Connections are devices used to join structural elements together to safely transfer forces between them. There are different types of connections classified by their means of connection, such as welded, riveted, and bolted, and by the forces transferred, such as truss connections, fully restrained connections, and partially restrained connections. Fully restrained connections provide continuity between structural members and allow over 90% of moment to be transferred to provide greater flexural resistance. Partially restrained connections have less rigidity than fully restrained connections and allow some percentage of moment and full shear to be transferred. Semi-rigid connections provide rigidity between fully restrained and simple connections and transfer approximately 20-90% of moment.
The document discusses structural steel construction, including the various methods used such as beam and column construction, long span construction, and wall bearing construction. It describes the common structural steel members like columns, beams, joists, and trusses that are erected and secured together using fastening systems like bolts and welds to form the structural framework. Details provided on erection plans guide the fabrication and installation of the different steel components.
Prestressed concrete combines high-strength concrete and high-strength steel in an active manner by tensioning steel tendons and holding them against the concrete, putting it into compression. This transforms concrete from a brittle to a more elastic material. It allows for optimal use of each material's properties and better behavior under loads. Prestressed concrete was pioneered in the 1930s and its use has expanded, finding applications in bridges and other structures. Common methods are pretensioning and post-tensioning, using various tendon types, with bonded or unbonded configurations. Tensioning is done using mechanical, hydraulic, electrical or chemical devices.
This document provides guidance on the design of lacing and battens for built-up compression members. It discusses the key design considerations and calculations for both single and double lacing systems, including the angle of inclination, slenderness ratio, effective lacing length, bar width and thickness. Similar guidelines are given for battens, covering spacing, thickness, effective depth, transverse shear and overlap. The document also includes an example problem on designing a slab foundation for a column with given load and material properties.
This document provides an overview of the design of steel beams. It discusses various beam types and sections, loads on beams, design considerations for restrained and unrestrained beams. For restrained beams, it covers lateral restraint requirements, section classification, shear capacity, moment capacity under low and high shear, web bearing, buckling, and deflection checks. For unrestrained beams, it discusses lateral torsional buckling, moment and buckling resistance checks. Design procedures and equations for determining effective properties and capacities are also presented.
This document summarizes the key aspects of flat slab construction and design according to Indian code IS 456-2000. It defines flat slabs as slabs that are directly supported by columns without beams, and describes four common types based on whether drops and column heads are used. The main topics covered include guidelines for proportioning slabs and drops, methods for determining bending moments and shear forces, requirements for slab reinforcement, and an example problem demonstrating the design of an interior flat slab panel.
In science, buckling is a mathematical instability, leading to a failure mode.
Buckling is characterized by a sudden sideways failure of a structural member subjected to high compressive stress, where the compressive stress at the point of failure is less than the ultimate compressive stress that the material is capable of withstanding
This document provides information on industrial buildings, including their components and factors to consider in design. Key points include:
- Industrial buildings are used for manufacturing and storage by industries and include steel plants, warehouses, and factories.
- Site selection considers access, raw materials, utilities, land characteristics, and transportation.
- Major components include the roof, trusses, purlins, girts, bracing, and foundations.
- Design considerations cover roofing/wall materials, bay widths, structural framing, truss configurations, and bracing to resist lateral loads.
The document discusses the design of steel structures according to BS 5950. It provides definitions for key terms related to steel structural elements and their design. These include beams, columns, connections, buckling resistance, capacity, and more. It then discusses the design process and different types of structural forms like tension members, compression members, beams, trusses, and frames. The properties of structural steel and stress-strain behavior are also covered. Methods for designing tension members, including consideration of cross-sectional area and end connections, are outlined.
This document discusses different types of columns used in construction. It defines a column as a structural member subjected to compressive axial loads. Columns are classified as long, short, or intermediate based on their length-to-minimum radius of gyration ratio. Long columns have a ratio greater than 50, short columns less than 15-50, and intermediate between 30-100. The document provides examples of column types and discusses effective length, radius of gyration, buckling load, and Euler's formula for calculating crippling load.
A system of prestressing involves tensioning tendons and securing them firmly to concrete. There are two main types: pre-tensioning and post-tensioning. Pre-tensioning involves pulling tendons tight between anchored abutments before concrete is poured. The Hoyer or long-line pre-tensioning system uses bulkheads to stretch wires over which molds are placed for concrete pouring. The Freyssinet system was the first post-tensioning method, using a cable of high-strength wires grouted into a duct within the concrete beam. Wires are anchored using conical plugs pushed into holes in concrete cylinders after jacking. The Magnel Blaton system tensions wires in pairs using sandwich plates
The document discusses limit state design of reinforced concrete structures. It introduces limit states as conditions where the structure becomes unfit for use, including limit states of strength and serviceability. Limit state design involves characterizing loads and resistances as random variables and using partial safety factors on loads and resistances to achieve a target reliability. The document outlines the general principles of limit state design according to Indian Standard code IS 800, including defining actions, factors governing strength limits, and serviceability limits related to deflection, vibration and durability.
This document provides an overview of the design of compression members (columns) in reinforced concrete structures. It discusses various types of columns based on reinforcement, loading conditions, and slenderness ratio. It describes the classification of columns as short or slender. The document also covers effective length, braced vs unbraced columns, codal provisions for reinforcement, and functions of longitudinal and transverse reinforcement. Key points include types of column reinforcement, minimum reinforcement requirements, cover requirements, and assumptions for the limit state of collapse under compression.
This document discusses post-tensioning devices and systems. Post-tensioning involves applying tension to tendons placed in ducts within hardened concrete. There are two main types: bonded uses grout in the ducts while unbonded does not. Key devices include ducts, anchoring devices, jacks and optional couplers and grouting equipment. Common anchoring principles are wedge action, direct bearing and looping wires. More than 64 post-tensioning systems have been patented worldwide with the Freyssinet system most common in India.
Post-tensioning is an effective alternative for earthquake-prone regions and dense populations in India. It has advantages over ordinary reinforced concrete like higher seismic resilience, less concrete usage, stiffer foundations, and faster construction. Post-tensioning involves threading steel tendons through ducts and tensioning them after concrete pouring. It provides better crack control, economy, quality, and efficiency. While widely used in other countries, post-tensioning is not yet common in India but has applications in slabs, buildings, and foundations.
The document discusses the design of footings for structures. It begins by explaining that footings are needed to transfer structural loads from members made of materials like steel and concrete to the underlying soil. It then describes different types of shallow and deep foundations, including spread, strap, combined, and raft footings. The document provides details on designing isolated and combined footings to resist vertical loads and moments based on provisions in IS 456. It also discusses wall footings and combined footings that support multiple columns. In summary, the document covers the purpose of footings, various footing types, and design of isolated and combined footings.
The document discusses different methods of post-tensioning concrete structures. It describes the Freyssinet system as the first introduced method using steel wires grouped into cables with a helical spring. The Magnel Blaton system stresses wires two at a time using sandwich plates and wedges. The Gifford Udall system uses single wires stressed independently with double-acting jacks and tube or plate anchorages. The Lee McCall system prestresses steel bars using threaded bars tightened with nuts against bearing plates.
This document discusses riveted connections and their design. It covers the different types of riveted joints like lap joints and butt joints. It provides specifications for riveted connections like the gross diameter of rivets, gauge, pitch and edge distance. It also discusses the types of failures in riveted connections and how to calculate the strength of riveted joints based on the strength of rivets in shear and bearing and the strength of plates in tension. The efficiency of riveted joints is defined. Examples of calculating rivet values are also provided.
This document discusses the design of compression members subjected to axial load and biaxial bending. It introduces the concept of biaxial eccentricities and explains that columns should be designed considering possible eccentricities in two axes. The document outlines the method suggested by IS 456-2000, which is based on Breslar's load contour approach. It relates the parameter αn to the ratio of Pu/Puz. Finally, it provides a step-by-step process for designing the column section, which involves determining uniaxial moment capacities, computing permissible moment values from charts, and revising the section if needed. It also briefly mentions the simplified method according to BS8110.
This document discusses different methods of prestressing concrete, including pretensioning and post-tensioning. Pretensioning involves stressing steel tendons before placing concrete around them, while post-tensioning involves stressing tendons after the concrete has cured using hydraulic jacks. Post-tensioning allows for longer spans, thinner slabs, and more architectural freedom compared to conventional reinforced concrete or pretensioned concrete. Common applications of post-tensioning include parking structures, bridges, and building floors and roofs.
Connections are devices used to join structural elements together to safely transfer forces between them. There are different types of connections classified by their means of connection, such as welded, riveted, and bolted, and by the forces transferred, such as truss connections, fully restrained connections, and partially restrained connections. Fully restrained connections provide continuity between structural members and allow over 90% of moment to be transferred to provide greater flexural resistance. Partially restrained connections have less rigidity than fully restrained connections and allow some percentage of moment and full shear to be transferred. Semi-rigid connections provide rigidity between fully restrained and simple connections and transfer approximately 20-90% of moment.
The document discusses structural steel construction, including the various methods used such as beam and column construction, long span construction, and wall bearing construction. It describes the common structural steel members like columns, beams, joists, and trusses that are erected and secured together using fastening systems like bolts and welds to form the structural framework. Details provided on erection plans guide the fabrication and installation of the different steel components.
The document discusses the history and development of steel as a building material. It describes how early iron extraction methods led to wrought iron with low strength, and how later techniques on like the Bessemer process improved steel production. Major historical structures that demonstrated the growing use of iron and steel in construction are highlighted, from 18th century cast iron bridges to tall skyscrapers in the early 20th century. The properties and classifications of steel per various codes and standards are also covered.
Connections are critical structural elements that join members in steel structures. Common connection types include bolted, welded, and bolted-welded combinations. Connections are classified based on the connecting medium, type of forces transmitted, and elements joined. Riveted connections were previously common but have been replaced by bolted connections which are faster and cheaper to install. Welded connections provide rigidity but require careful design to avoid cracking. Modern connections often combine bolting and welding for strength and economy. Shear and moment connections behave differently in transmitting forces between members like beams and columns. Proper connection design is important for structural integrity and safety.
This document discusses points and crossings in railway tracks. It defines points and crossings as arrangements that guide trains during directional changes. Points divert vehicles, while crossings provide gaps in rails for flanged wheels to roll over. The key components of a point and crossing assembly are the point, lead, and crossing element. Crossings introduce gaps where tracks cross to allow wheels to pass between tracks. Points and crossings are necessary because railway vehicles have inside wheel flanges and require special arrangements to navigate the rails and change tracks or directions.
This document discusses various methods for measuring stream flow. There are direct and indirect methods. Direct methods like area-velocity measure discharge by determining the cross-sectional area and average velocity. Indirect methods relate discharge to easily measured water level/stage using structures or the slope-area method with Manning's equation. Accurate stage measurements are important for estimating discharge from stage-discharge curves developed through direct measurements.
Ch5 Plate Girder Bridges (Steel Bridges تصميم الكباري المعدنية & Prof. Dr. Me...Hossam Shafiq II
Plate girders are commonly used as main girders for short and medium span bridges. They are fabricated by welding together steel plates to form an I-shape cross-section, unlike hot-rolled I-beams. Plate girders offer more design flexibility than rolled sections as the plates can be optimized for strength and economy. However, their thin plates are more susceptible to various buckling modes which control the design. Buckling considerations of the compression flange, web in shear and bending must be evaluated to determine the plate girder's load capacity.
Points and crossings ( special assigments )hiranrathva
Points and crossings are arrangements that allow trains to move between tracks. They consist of movable rails called switches or tongues that can divert trains left or right. Crossings provide gaps in the rails so trains can move between intersecting tracks. Together, switches and crossings form turnouts that allow trains to change routes. Proper placement and angles of switches and crossings are necessary for train wheels to safely navigate between tracks.
This document discusses precipitation measurement and estimation. It begins by defining precipitation and its different types. It then discusses various methods for measuring precipitation, including manual and automatic rain gauges. It emphasizes the importance of establishing a raingauge network according to WMO recommendations to spatially average precipitation measurements over a region. The document concludes by outlining different methods that can be used to estimate missing precipitation data, including station averaging, normal ratio, inverse distance weighting, and regression techniques.
This document is a project report on the geometric design of railway tracks submitted by Mohit M. Jain to Gujarat Technological University in India. It introduces the topic of geometric design and its importance for ensuring safe and efficient train operation. The following chapters discuss geometric cross sections, gradients including different types, curves, superelevation, and gauge widening on curves. The report provides information on the key design considerations for railway tracks.
This document discusses railway engineering concepts related to points, crossings, and turnouts. It describes that a crossing allows the flanges of a railway vehicle to pass from one track to another where the gauges cross. A turnout uses lead rails and curved rails to divert rolling stock from one track to another. The key components of a turnout are tongue rails, stock rails, check rails, lead rails, a Vee crossing, and parts for operating the points. The document also describes different types of crossings, including acute angle, obtuse angle, and square crossings, as well as components like wing rails and check rails.
This lecture discusses the equilibrium of particles and free-body diagrams. It defines particle equilibrium as being at rest if originally at rest or having constant velocity if in motion. The condition for particle equilibrium is that the sum of all forces acting on the particle is zero. Examples of connections involving springs and cables/pulleys are provided. The procedure for drawing free-body diagrams involves outlining the particle, showing all known and unknown forces, and labeling the forces. Example problems are solved to demonstrate applications of these concepts.
This document provides an introduction to groundwater hydrology. It discusses key topics such as the hydrologic cycle, aquifers, water tables, wells, Darcy's law, and groundwater management. Shallow groundwater recharges more quickly than deep groundwater but is more prone to contamination. Aquifers are underground units that store and transmit water, and can be unconfined, confined, or semi-confined. The water table and piezometric surface indicate the level of groundwater in unconfined and confined aquifers respectively. Darcy's law describes the flow of water through porous media. Groundwater management aims to balance withdrawal and recharge to prevent water levels from dropping. Artificial recharge
This document provides information about the hydrological cycle and water budget. It begins with the objectives of understanding water sources and the hydrological cycle components of evaporation, precipitation, infiltration, runoff and subsurface flow. It then discusses the global water resources and usage, including increasing population growth. The bulk of the document defines and explains the various components of the hydrological cycle, including evaporation, condensation, precipitation types, interception, infiltration, subsurface flow, runoff and storage. It provides an example water balance equation and long-term water balance calculation. Finally, it briefly discusses the global water cycle and a typical hydrological cycle for the UAE.
IJCER (www.ijceronline.com) International Journal of computational Engineerin...ijceronline
The document discusses determining the fatigue behavior of engine damper cap screw bolts. It describes testing the bolts to determine their ultimate tensile strength, hardness, preload, and fatigue strength. Samples of the bolts were tested under various alternating loads with a constant mean load to generate an S-N curve showing their fatigue life. It was found that fatigue failure occurred in the threads due to high stress concentration, and the average preload of the bolts was determined to be 40,000 lbs using ultrasonic measurement.
IJCER (www.ijceronline.com) International Journal of computational Engineerin...ijceronline
The document discusses determining the fatigue behavior of engine damper cap screw bolts. It begins with an abstract that outlines testing cap screw bolts under different alternating loads to determine their fatigue strength using the S-N method. It then provides background on issues like insufficient bolt preload leading to failure. The document describes testing the mechanical properties of damper cap screw bolts, including hardness, ultimate tensile strength from tension tests, and evaluating their chemical composition. It aims to determine the cap screw bolts' fatigue strength and failure locations under fatigue testing.
Structural Connection Design & Construction Aspect .pptxahmad705917
Structural connection design and constructability are discussed. Connections are critical for transferring forces between structural members safely and economically. Simple bolted connections are commonly used due to ease of fabrication and ability to accommodate site adjustments. Connection types include shear, moment, and splice connections. Failure modes like bolt shear, bearing, and block shear are reviewed. Constructability considerations include connection design for simplicity and repetition to reduce erection costs.
Instruction manual for installing high strength bolts with direct tension ind...aiax69
This document provides instructions for installing high-strength bolts with direct tension indicators (DTIs) according to ASTM F959M standards. It describes the theory behind high-strength bolting, explains how DTIs indicate proper bolt tensioning, and provides step-by-step instructions for installing bolts using both plain and coated DTIs. The instructions cover approved installation methods and addressing common issues like proper washer usage and avoiding spinning bolts during tensioning.
Multi-StageSheet Metal Fromed Bolted Fastener DesignMark Brooks
This document discusses the development of a multi-stage sheet metal fastening design that eliminates nuts to reduce costs and improve manufacturing efficiency. Testing showed that while extruded, rivet, and PEM nuts exceeded torque specifications, shear/tap fasteners only marginally met specifications, failing through thread tear. To breakthrough this technology barrier, the basics of thread forming were revisited. Roll-forming threads through compression may improve performance over cutting threads.
Strength Calculation and Dimensioning of Joints.pptxNigussieAdem2
This document discusses various types of mechanical joints and fasteners, including bolted, welded, and riveted joints. It covers topics such as bolt materials and strengths, thread standards and definitions, stress areas of bolts, stiffness of fasteners and clamped parts, and force analysis of power screws. The document contains definitions of key terms related to bolts, screws, threads and joints. It also provides equations for calculating forces and torques in bolted and power screw connections.
Strength calculation and Dimension of Joints.pptxNigussieAdem2
This document discusses various types of mechanical joints and fasteners, including bolted, welded, and riveted joints. It focuses on bolted connections, describing bolt materials, thread standards, stress areas, stiffness calculations, and tension in joints. It also covers power screws, providing definitions and analyzing the forces involved when using power screws to lift or lower a load. It describes the conditions required for a screw to be self-locking.
This document discusses different methods of ligation in orthodontics. It describes conventional elastic or metallic ligation as well as newer self-ligating methods built into brackets. The three most common ligation systems are discussed as active/passive self-ligation and conventional elastic ligation. Research has shown passive self-ligation decreases forces and moments compared to elastic ligation. Tiebacks and lacebacks are described as methods to retract canines into extraction spaces, with tiebacks using elastics and lacebacks using direct wires from molars to canines.
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Prestressed concrete is concrete in which internal stresses are introduced to counteract external loads. Tendons are stretched elements that impart prestress, and anchorage devices enable the tendons to impart and maintain prestress. There are two main methods - pretensioning, where tendons are tensioned before concrete is cast, and post-tensioning, where tendons are tensioned against hardened concrete. Prestressed concrete uses high-strength materials like cement, concrete, and steel tendons or strands to achieve its compressive strength and durability advantages over reinforced concrete.
Threaded fasteners such as bolts and nuts are used to join machine parts. They allow parts to be dismantled without damage. Threaded joints provide clamping force through wedge action of threads. They are reliable, have small dimensions, and can be positioned vertically, horizontally, or inclined. However, they require holes which cause stress concentrations and can loosen under vibration. Bolts have heads and threaded shanks, while nuts have internal threads. Washers distribute load and prevent marring. Bolts are subjected to both tension and shear stresses, and standard nuts have a height of 0.8 times the bolt diameter to prevent shear failure. Eccentric loads on bolts cause additional stresses.
This document provides information on selecting fastener materials and their mechanical properties. It discusses the most common material, carbon steel, and its various grades. It also covers stainless steel types including austenitic, martensitic, and ferritic, and provides examples of common grades for each type. Additional materials discussed include alloy steels and precipitation hardening stainless steel. The document aims to provide basic knowledge on fastener materials to help with evaluating the right material for an application.
The document discusses the design of various types of screw fasteners. It describes screw threads as helical grooves cut into cylindrical surfaces. Screw joints are commonly used for assembly and have advantages of being convenient to assemble/disassemble, reliable, and inexpensive due to standardization. The main types of screw fasteners are bolts, screws, studs, tapping screws, and set screws. Stresses in screw joints include tension, torsional shear, shear across threads, crushing stress, and bending stress. Screw joints are also subjected to stresses from initial tightening and external loads. Design considerations are discussed for bolted joints under eccentric loading parallel or perpendicular to the bolt axis.
The document provides instructions for operating portable Rockwell/Brinell hardness testers. It describes safety precautions for eye and hand protection. It explains that the testers use a pin that shears under a calibrated force to make indentations for measuring hardness. Hardness is determined by looking up the indentation size in supplied tables. The document provides details on setup, operation, factors affecting accuracy, and interpretation of results for both clamped and hammer-impact test methods.
The document discusses locking assemblies used for belt drums that experience bending loads. It provides details on:
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The document describes a new type of cable connector called SICON that uses a stepless shear bolt. Key points:
1) SICON uses a stepless shear bolt that does not have predetermined breaking points, allowing it to achieve optimum clamping force for any conductor size.
2) Previous multi-stage shear bolts had breaking points that created discontinuities and did not allow maximum force. SICON's bolt breaks smoothly.
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External fixators are devices used to stabilize fractures located outside the body. They minimize metal inside tissues and allow for easy wound access. Pin fixators use cantilevered pins for stabilization while ring fixators form an exoskeleton around the limb for deformity correction. Proper pin placement and preloading are important for stability at the pin-bone interface. Dynamization through loosening of the fixator over time stimulates healing. External fixators are indicated for open fractures, bone defects, and limb lengthening and have advantages of being minimally invasive.
Bolts are widely used as critical load transferring components. Despite the importance to integrity and safety, little attention has been paid to the correct use of bolts and bolting materials.
Couplings are used to connect two rotating shafts and transmit torque from one to the other. There are two main types of couplings: rigid couplings for perfectly aligned shafts, and flexible couplings for shafts with misalignment which absorb shocks and vibrations. Common rigid couplings include sleeve, flange, and split-muff couplings which connect shafts through a sleeve or bolted flanges. Flexible bush pin couplings connect shafts through pins with rubber bushes to absorb shocks and compensate for misalignment.
How to Guarantee Design-Life of Concrete Structures-MasterBuilder-July 2016Dr.Subramanian Narayanan
1) Concrete structures designed for 50-60 years of service life often deteriorate more quickly, with maintenance costs comprising 40-50% of construction spending in some places.
2) Roman structures like the Pantheon, built over 2000 years ago using slow-hardening lime cements, remain in excellent condition, while 20th century structures using Portland cement often deteriorate within 10-20 years.
3) To reliably achieve 100+ year design lives, concrete must be properly specified, mixed, placed, compacted and cured, rather than just focusing on short-term strength as was common practice.
Three futuristic composite bridge technologies - Bridge in a Backpack, Hybrid-Composite Beam, and ProCoBeam - are described that result in fast-track construction and more sustainable bridges with expected lifespans over 100 years. The Bridge in a Backpack uses fiber reinforced polymer tubes filled with self-consolidating concrete as main load-bearing elements. The Hybrid-Composite Beam has a fiber reinforced polymer shell housing a self-consolidating concrete arch tied by galvanized prestressing strands. ProCoBeam uses a shear composite dowel to connect a bottom steel T-section to a top concrete T-section.
The document describes the Access to Computer Education series which introduces primary and middle school students to computers and programming concepts. The series includes eight books, with books 1-2 being new and books 3-8 revised. It emphasizes programming concepts like MSWLogo, QBASIC, object-oriented programming, C++, Java, networking and ethics. The course includes books, an e-book, teacher's manual and website. Key features are learning tools like quick tips and definitions, and assessment tools like exercises, tests and projects to review progress.
This document provides tips on time management. It begins with an outline of topics to be covered, including why time management is important, goals and planning, to-do lists, managing paperwork and technology, and general advice. Key tips include setting goals and priorities, using a to-do list, minimizing interruptions, learning to delegate tasks, keeping meetings efficient, and taking vacations away from work. The document recommends time management tools like planners and recommends the book "The Seven Habits of Highly Effective People" for additional guidance.
This document discusses various earthquake design considerations for buildings. It notes that buildings with unequal mass distribution, soft ground floors, or uneven structural elements can twist during shaking. Different buildings respond differently to ground vibrations depending on the period of earthquake waves. Indian design codes like IS 13920 and IS 1893 provide guidelines for ductile reinforcement details. Proper detailing of beams, columns, joints, walls and foundations is necessary to resist seismic forces. Base isolation and damping devices can also help reduce earthquake shaking and damage.
The document discusses various topics related to earthquakes and seismic design including:
1. Plate tectonics theory explains how the lithosphere is broken into plates that move relative to each other, causing earthquakes along plate boundaries.
2. Earthquakes are measured on the Richter scale and can cause damage depending on factors like magnitude, distance from epicenter, and soil properties.
3. Seismic design codes aim to prevent collapse from major earthquakes through concepts like ductility, overstrength, and redundancy while allowing some damage from minor quakes.
4. Dynamic analysis methods like response spectrum and time history are used to design important structures, while the equivalent lateral force method is commonly used for other
In our second session, we shall learn all about the main features and fundamentals of UiPath Studio that enable us to use the building blocks for any automation project.
📕 Detailed agenda:
Variables and Datatypes
Workflow Layouts
Arguments
Control Flows and Loops
Conditional Statements
💻 Extra training through UiPath Academy:
Variables, Constants, and Arguments in Studio
Control Flow in Studio
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The best thing about databases is that they always work as intended, and never suffer any downtime. You'll never see a system go offline because of a database outage. In this talk, Bo Ingram -- staff engineer at Discord and author of ScyllaDB in Action --- dives into an outage with one of their ScyllaDB clusters, showing how a stressed ScyllaDB cluster looks and behaves during an incident. You'll learn about how to diagnose issues in your clusters, see how external failure modes manifest in ScyllaDB, and how you can avoid making a fault too big to tolerate.
This talk will cover ScyllaDB Architecture from the cluster-level view and zoom in on data distribution and internal node architecture. In the process, we will learn the secret sauce used to get ScyllaDB's high availability and superior performance. We will also touch on the upcoming changes to ScyllaDB architecture, moving to strongly consistent metadata and tablets.
Supercell is the game developer behind Hay Day, Clash of Clans, Boom Beach, Clash Royale and Brawl Stars. Learn how they unified real-time event streaming for a social platform with hundreds of millions of users.
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inQuba Webinar Mastering Customer Journey Management with Dr Graham HillLizaNolte
HERE IS YOUR WEBINAR CONTENT! 'Mastering Customer Journey Management with Dr. Graham Hill'. We hope you find the webinar recording both insightful and enjoyable.
In this webinar, we explored essential aspects of Customer Journey Management and personalization. Here’s a summary of the key insights and topics discussed:
Key Takeaways:
Understanding the Customer Journey: Dr. Hill emphasized the importance of mapping and understanding the complete customer journey to identify touchpoints and opportunities for improvement.
Personalization Strategies: We discussed how to leverage data and insights to create personalized experiences that resonate with customers.
Technology Integration: Insights were shared on how inQuba’s advanced technology can streamline customer interactions and drive operational efficiency.
Automation Student Developers Session 3: Introduction to UI AutomationUiPathCommunity
👉 Check out our full 'Africa Series - Automation Student Developers (EN)' page to register for the full program: http://bit.ly/Africa_Automation_Student_Developers
After our third session, you will find it easy to use UiPath Studio to create stable and functional bots that interact with user interfaces.
📕 Detailed agenda:
About UI automation and UI Activities
The Recording Tool: basic, desktop, and web recording
About Selectors and Types of Selectors
The UI Explorer
Using Wildcard Characters
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Conversational agents, or chatbots, are increasingly used to access all sorts of services using natural language. While open-domain chatbots - like ChatGPT - can converse on any topic, task-oriented chatbots - the focus of this paper - are designed for specific tasks, like booking a flight, obtaining customer support, or setting an appointment. Like any other software, task-oriented chatbots need to be properly tested, usually by defining and executing test scenarios (i.e., sequences of user-chatbot interactions). However, there is currently a lack of methods to quantify the completeness and strength of such test scenarios, which can lead to low-quality tests, and hence to buggy chatbots.
To fill this gap, we propose adapting mutation testing (MuT) for task-oriented chatbots. To this end, we introduce a set of mutation operators that emulate faults in chatbot designs, an architecture that enables MuT on chatbots built using heterogeneous technologies, and a practical realisation as an Eclipse plugin. Moreover, we evaluate the applicability, effectiveness and efficiency of our approach on open-source chatbots, with promising results.
2. Why Connection Failure
Should be Avoided?
A connection failure may be lead to a
catastrophic failure of the whole structure
Normally, a connection failure is not as
ductile as that of a steel member failure
For achieving an economical design, it is
important that connectors develop full or
a little extra strength of the members, it
is joining.
Connection failure may be avoided by
adopting a higher safety factor for the
joints than the members.
2 Dr. N. Subramanian
3. Classification of Connections
Method of fastening: rivets, bolts and
welding.
Connection rigidity: simple, rigid or
semi-rigid.
Joint resistance: Bearing connections
and friction connections
Fabrication location: Shop or field
connections.
Joint location: Beam-column, beam-to
beam, column to foundation
3 Dr. N. Subramanian
4. Classification of Connections
(cont.)
Connection geometry: Single web
angle, single plate, double web angle,
top and seat angles (with and without
stiffeners), end plates, or header plate,
welded connections using plates and
angles, etc.
Type of force transferred across the
structural connection: Shear
connections, shear and moment
connection or simply moment
connection, tension or compression,
tension or compression with shear.
4 Dr. N. Subramanian
5. Classification Based on
Joint Rigidity
Rigid: That develop the full moment capacity
of connecting members and retain the
original angle between the members under
any joint rotation. Rotational movement of the
joint will be very small
Simple: No moment transfer is assumed
between the connected parts and hence
assumed as hinged (pinned). Rotational
movement of the joint will be large.
Semi-Rigid: May not have sufficient rigidity to
hold the original angles between the members
and develop less than the full moment capacity
of the connected members. In reality all the
connections will be semi-rigid only.
5 Dr. N. Subramanian
8. Rivets and Riveted Connections
Riveting not used now due to:
The necessity of preheating
the rivets prior to driving
Labour costs associated with
large riveting crews.
Cost involved in careful
inspection and removal of
poorly installed rivets
High level of noise associated
with driving rivets
8 Dr. N. Subramanian
9. Types of Bolts
Unfinished bolts or black bolts or C
Grade bolts (IS: 1363-1992)-bearing type
connections
Turned bolts - Expensive & used in Spl. jobs
Precision (A-Grade)& Semi-precision
(B-Grade) bolts (IS: 1364-1992) -They
are used when no slippage is permitted
Ribbed bolts (Rarely used in ordinary steel
structures)
High strength bolts (IS: 3757-1985 and
IS:4000 - 1992)-Friction type connections
9 Dr. N. Subramanian
11. Hexagonal Head Black
Bolt and Nut (IS 1363)
Figures in brackets are for High-strength Bolts & Nuts
Black bolts are inserted in clearance holes of about 1.5mm to
2mm more than the bolt diameter and then tightened through
the nuts.
11 Dr. N. Subramanian
12. Tensile Properties of Fasteners
For grade 4.6 bolts, nuts of grade 4 are used and for grade 8.8, nuts of grade 8 or 10 are used.
In property class 4.6, the number 4 indicates 1/100th the
nominal ultimate tensile strength in N/mm2 and the number 6
indicates the ratio of yield stress to ultimate stress, expressed
as a percentage. Thus the ultimate tensile strength of class 4.6
bolt is 400 N/mm2 and yield strength is 0.6 times 400, which
is 240 N/mm2
12 Dr. N. Subramanian
13. Dimensions of Grade 4.6-
Hexagon Head Bolts (IS 1364)
Sizes in Brackets not preferred.
13 Dr. N. Subramanian
14. High-Strength Bolts (IS 3757)
Made from bars of medium carbon steel.
Bolts of property class 8.8 and 10.9 are commonly used.
14 Dr. N. Subramanian
15. High-Strength Bolts (cont.)
The material of the bolts do not have a
well defined yield point.
Instead of using yield stress, a so-
called proof load is used.
The proof load is the load obtained by
multiplying the tensile stress area
(approximately equal to 0.8 times the
shank area of bolt) by the proof stress.
In IS:800 the proof stress is taken as
0.7 times the ultimate tensile stress of
the bolt.
15 Dr. N. Subramanian
16. High-Strength Bolts (cont.)
They are identified
by manufacturer’s
identification symbol
and property class
identification symbol
8 S or 8.8 S or 10 S
or 10.9 S which will
be embossed on the
Source: heads of these bolts.
www.nichiasteel.co.jp
Class 10.9 bolts should not be hot-dip galvanized
16 Dr. N. Subramanian
17. High-Strength Friction Grip
(HSFG) Bolts
Special techniques are used for tightening
the nuts to induce a specified initial
tension in the bolt (called the proof-load),
which causes sufficient friction between
the faying faces.
Such bolts are called High-Strength
Friction Grip bolts (HSFG).
Due to this friction, the slip in the joint is
eliminated; joints with HSFG bolts are
called non-slip connections or friction
type connections
17 Dr. N. Subramanian
18. Bolt Tightening Techniques
When slip resistant connections are not
required, high strength bolts are
tightened to a ‘snug-tight’ using an
ordinary spud wrench.
When slip resistant connections are
desired with HDFC bolts, three methods
are used:
Turn-of-the-nut tightening (part–turn
method) –Cheap, more reliable, and
common method.
Direct tension indicator tightening,
Calibrated wrench tightening (torque
control method).
18 Dr. N. Subramanian
20. Turn-of-the nut Tightening
In the American practice, 1/3 turn of the nut is prescribed
for bolt length less than 4 d, 1/2 turn of the nut for bolt
lengths from 4 to 8 d or 200 mm and 2/3 turn of the nut for
bolt lengths greater than 8 d or 200 mm, where d is the
diameter of bolt (Salmon and Johnson, 1996). The bolts are
tensioned using 1/8 turn increments.
20 Dr. N. Subramanian
21. Behaviour of bolt-Turn-of-
the-nut Method
21 Dr. N. Subramanian In this method the bolt deformation is
a critical factor
22. Direct Tension Indicator
Tightening
There are two types of proprietary load – indication
devices.
The first type of device indicates the load by producing a
measurable change in gap between the nut and the gripped
material.
22 Dr. N. Subramanian
23. Direct Tension Indicator
Tightening (cont)
In the second type, the bolt is tightened by
turning a nut, which has a protruding nib; the
tightening is continued till the nib shears off.
23 Dr. N. Subramanian
24. Calibrated Wrench tightening
Wrenches are calibrated by
tightening, in a hydraulic
tension-measuring device,
using a minimum of three bolts
of the same diameter.
Impact wrenches are set to
stall when the prescribed bolt
tension is reached. A click
sound can be heard and felt
when the set torque is
reached.
Manual torque wrenches have
a torque indicating device,
using which the torque
required to produce the initial
tension is measured.
24 Dr. N. Subramanian
25. Advantages of
Bolted connections
Bolted connections offer the following
advantages over riveted or welded
connections:
Use of unskilled labour and simple tools
Noiseless and quick fabrication
No special equipment/process needed for
installation
Fast progress of work
Accommodates minor discrepancies in
dimensions
The connection supports loads as soon as the
bolts are tightened (in welds and rivets,
cooling period is involved).
Main drawback of black bolt is the slip
of the joint when subjected to loading
25 Dr. N. Subramanian
27. Advantages of HSFG Bolts
HSFG bolts do not allow any slip between the
elements connected, especially in close tolerance
holes, Thus they provide rigid connections.
Because of the clamping action, load is
transmitted by friction only and the bolts are not
subjected to shear and bearing.
Due to the smaller number of bolts, the gusset
plate sizes are reduced.
Deformation is minimized.
Holes larger than usual can be provided to ease
erection and take care of lack-of-fit. However
note that the type of hole will govern the strength
of the connection.
Noiseless fabrication, since the bolts are
tightened with wrenches.
27 Dr. N. Subramanian
28. Advantages of HSFG Bolts
The possibility of failure at the net section under
the working loads is eliminated.
Since the loads causing fatigue will be within
proof load, the nuts are prevented from loosening
and the fatigue strength of the joint will be
greater than in welded/connections.
Since the load is transferred by friction, there is no
stress concentration in the holes.
Unlike riveted joints, few persons are required for
making the connections.
No heating is required and no danger of tossing of
bolt. Thus safety of the workers is enhanced.
Alterations, if any (e.g. replacement of defective
bolt) is done easily than in welded connections.
28 Dr. N. Subramanian
29. Drawbacks of HDFC Bolts
Bolting usually involves a significant
fabrication effort to produce the bolt holes
and associated plates or cleats.
Special procedures are required to ensure
that the clamping actions required for
preloaded friction-grip joints are
achieved.
The connections with HSFG bolts may not
be as rigid as a welded connection.
HSFG bolts are about 50% higher than
black bolts
The percentage elongation at failure is
12% only.
29 Dr. N. Subramanian
30. Bolt Holes
Bolt holes are usually drilled.
IS: 800 allows punched holes only in
materials whose yield stress (fy) does not
exceed 360 MPa and where thickness
does not exceed (5600/fy) mm.
Bolt holes are made larger than the bolt
diameter to facilitate erection.
Oversize holes should not exceed 1.25d or
(d+8) mm in diameter, where d is the
nominal bolt diameter in mm.
Slotted hole [provided to accommodate
movements) should not exceed 1.33d in
length (for short slotted hole) and 2.5 d in
length (for long slotted hole).
30 Dr. N. Subramanian
31. Pitch, Staggered holes &
Gauge
The edge
distance
should be
sufficient for
bearing
capacity and
to provide
space for bolt
head, washer
and nut.
A minimum spacing of 2.5 times the nominal diameter of
the fastener is specified in the code to ensure that there
is sufficient space to tighten the bolts, to prevent
overlapping of the washers and to provide adequate
resistance to tear-out of the bolts.
31 Dr. N. Subramanian
32. Bolt Dia, Pitch & Edge
Distances as per IS 800
32 Dr. N. Subramanian
34. Note on IS Rolled Sections
Bolting is often poorly executed:
Shank gets bent due to tapered flange
To avoid it use
Tapered washers
(IS 5372/IS 5374)
34 Dr. N. Subramanian