Here are the key steps to design a double angle tension member and gusset plated bolted connection system to carry a factored tensile load of 100 kips:
1. Select the size of double angle member based on required strength and other design considerations like availability, cost, etc. Let's assume we select a pair of L6x6x1/2 angles.
2. Check the net tensile strength of the selected double angle section. For L6x6x1/2 angles, the net tensile strength would be greater than 100 kips based on the properties provided in the steel manual.
3. Design the bolted connection between the double angle member and gusset plate. Select
1) Connections are an important part of steel structures as they allow different structural elements to act together as a single unit by transferring forces between members. Common types of connections include riveted, bolted, welded, and pinned connections.
2) Bolted connections use bolts with heads and threaded ends to connect structural elements. Steel washers are often included to distribute clamping pressure and prevent bearing on connected pieces.
3) Design of bolted connections considers factors like bolt grade, type of joint, edge and end distances, pitch, and capacity in shear, tension, and bearing to ensure the connection can safely transfer loads between members. Failure can occur in bolts or connected elements due to various limit
23-Design of Column Base Plates (Steel Structural Design & Prof. Shehab Mourad)Hossam Shafiq II
This document discusses the design of column base plates to resist both axial loads and bending moments. It provides equations to calculate stresses on the base plate and footing. It then gives an example of designing a base plate for a column supporting an axial load of 1735 kN and bending moment of 200 kN.m. The design process involves calculating eccentricity, base plate dimensions, stresses on the footing, required plate thickness, and checking bending in two directions. The example concludes by specifying a base plate of dimensions 750mm x 500mm x 40mm that satisfies all design requirements.
This document presents an example of analysis design of slab using ETABS. This example examines a simple single story building, which is regular in plan and elevation. It is examining and compares the calculated ultimate moment from CSI ETABS & SAFE with hand calculation. Moment coefficients were used to calculate the ultimate moment. However it is good practice that such hand analysis methods are used to verify the output of more sophisticated methods.
Also, this document contains simple procedure (step-by-step) of how to design solid slab according to Eurocode 2.The process of designing elements will not be revolutionised as a result of using Eurocode 2. Due to time constraints and knowledge, I may not be able to address the whole issues.
The document provides details on the design of a reinforced concrete column footing to support a column load of 1100kN from a 400mm square column. It describes the design process which includes determining the footing size, calculating bending moment, reinforcement requirements, checking shear capacity and development length. The design example shows a 3.5m x 3.5m square footing with 12mm diameter bars at 100mm c/c is adequate to support the given load based on the specified material properties and design codes. Reinforcement and footing details are also provided.
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.
The document provides steps for designing different structural elements:
1. Design of a beam subjected to torsion including calculation of torsional and bending moments, determination of steel requirements, and detailing.
2. Design of continuous beams involving calculation of bending moments and shears, reinforcement sizing, shear design, deflection check, and detailing including curtailment.
3. Design of circular water tanks with both flexible base and rigid base using approximate and IS code methods. This includes sizing hoop and vertical tension reinforcement, sizing wall thickness, designing cantilever sections and base slabs, and providing detailing diagrams.
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,
This document discusses tension members in structural engineering. It defines tension members as linear members that experience axial forces that elongate or stretch the member. Examples given include ropes, ties in trusses, suspenders in bridges. The document discusses the types of cross-sections used for tension members like angles, channels, rods. It also discusses the calculation of net effective sectional area and provides examples. Other topics covered include types of failures in tension members, design strength calculations, limiting slenderness ratios, tension splices, and lug angles.
1) Connections are an important part of steel structures as they allow different structural elements to act together as a single unit by transferring forces between members. Common types of connections include riveted, bolted, welded, and pinned connections.
2) Bolted connections use bolts with heads and threaded ends to connect structural elements. Steel washers are often included to distribute clamping pressure and prevent bearing on connected pieces.
3) Design of bolted connections considers factors like bolt grade, type of joint, edge and end distances, pitch, and capacity in shear, tension, and bearing to ensure the connection can safely transfer loads between members. Failure can occur in bolts or connected elements due to various limit
23-Design of Column Base Plates (Steel Structural Design & Prof. Shehab Mourad)Hossam Shafiq II
This document discusses the design of column base plates to resist both axial loads and bending moments. It provides equations to calculate stresses on the base plate and footing. It then gives an example of designing a base plate for a column supporting an axial load of 1735 kN and bending moment of 200 kN.m. The design process involves calculating eccentricity, base plate dimensions, stresses on the footing, required plate thickness, and checking bending in two directions. The example concludes by specifying a base plate of dimensions 750mm x 500mm x 40mm that satisfies all design requirements.
This document presents an example of analysis design of slab using ETABS. This example examines a simple single story building, which is regular in plan and elevation. It is examining and compares the calculated ultimate moment from CSI ETABS & SAFE with hand calculation. Moment coefficients were used to calculate the ultimate moment. However it is good practice that such hand analysis methods are used to verify the output of more sophisticated methods.
Also, this document contains simple procedure (step-by-step) of how to design solid slab according to Eurocode 2.The process of designing elements will not be revolutionised as a result of using Eurocode 2. Due to time constraints and knowledge, I may not be able to address the whole issues.
The document provides details on the design of a reinforced concrete column footing to support a column load of 1100kN from a 400mm square column. It describes the design process which includes determining the footing size, calculating bending moment, reinforcement requirements, checking shear capacity and development length. The design example shows a 3.5m x 3.5m square footing with 12mm diameter bars at 100mm c/c is adequate to support the given load based on the specified material properties and design codes. Reinforcement and footing details are also provided.
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.
The document provides steps for designing different structural elements:
1. Design of a beam subjected to torsion including calculation of torsional and bending moments, determination of steel requirements, and detailing.
2. Design of continuous beams involving calculation of bending moments and shears, reinforcement sizing, shear design, deflection check, and detailing including curtailment.
3. Design of circular water tanks with both flexible base and rigid base using approximate and IS code methods. This includes sizing hoop and vertical tension reinforcement, sizing wall thickness, designing cantilever sections and base slabs, and providing detailing diagrams.
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,
This document discusses tension members in structural engineering. It defines tension members as linear members that experience axial forces that elongate or stretch the member. Examples given include ropes, ties in trusses, suspenders in bridges. The document discusses the types of cross-sections used for tension members like angles, channels, rods. It also discusses the calculation of net effective sectional area and provides examples. Other topics covered include types of failures in tension members, design strength calculations, limiting slenderness ratios, tension splices, and lug angles.
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.
Lec11 Continuous Beams and One Way Slabs(1) (Reinforced Concrete Design I & P...Hossam Shafiq II
The document discusses reinforced concrete continuity and analysis methods for continuous beams and one-way slabs. It describes how steel reinforcement must extend through members to provide structural continuity. The ACI/SBC coefficient method of analysis is summarized, which uses coefficient tables to determine maximum shear forces and bending moments for continuous beams and one-way slabs under various loading conditions in a simplified manner compared to elastic analysis. Requirements for applying the coefficient method include having multiple spans with ratios less than 1.2, prismatic member sections, and live loads less than 3 times dead loads.
The document discusses different methods of designing concrete structures, focusing on the limit state method. It describes the limit state method's goal of achieving an acceptable probability that a structure will not become unsuitable for its intended use during its lifetime. The document then discusses stress-strain curves for concrete and steel. It covers stress block parameters and equations for calculating the depth of the neutral axis and moment of resistance for singly reinforced concrete beams. The document concludes by providing examples of analyzing an existing beam section and designing a new beam section.
Because of torsion, the beam fails in diagonal tension forming the spiral cracks around the beam. Warping of the section does not allow a plane section to remain as plane after twisting. Clause 41 of IS 456:2000 provides the provisions for
the design of torsional reinforcements. The design rules for torsion are based on the equivalent moment.
Design of Beam- RCC Singly Reinforced BeamSHAZEBALIKHAN1
Concrete beams are an essential part of civil structures. Learn the design basis, calculations for sizing, tension reinforcement, and shear reinforcement for a concrete beam.
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.
The document discusses machine foundations used in the oil and gas industry. It begins by introducing the different types of machines, such as centrifugal and reciprocating machines, and how they are classified based on speed. It then discusses the various types of foundations used to support these machines, including block foundations and frame foundations. The document outlines the inputs needed for foundation design, which include project specifications, soil parameters, and machine details from the vendor. It describes the process of analyzing machine foundations, including dynamic and static analyses. Key aspects like natural frequencies, displacements, and strength are evaluated.
The document provides a summary of modeling and analyzing slabs in ETABS, including:
1) Common assumptions made in slab modeling such as element type, meshing, shape, and acceptable error.
2) Steps for initial analysis including sketching expected results and comparing total loads.
3) Formulas and coefficients for calculating maximum bending moments in one-way and two-way slabs.
4) A process for designing solid slabs according to Eurocode 2 involving determining reinforcement ratios and areas.
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
This document discusses the analysis and design of reinforced concrete footings. It describes different types of footings including isolated, combined, continuous, and raft foundations. It also covers design considerations such as minimum thickness, concrete cover, reinforcement sizes and spacing, and critical sections. An example is provided to demonstrate the step-by-step design of an isolated square footing, calculating loads, sizing the footing, checking effective depth, determining steel requirements, and verifying hook and dowel bar needs.
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.
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 document discusses beams supported on an elastic foundation. It begins by introducing the Winkler foundation model and defining short, medium, and long beams based on the parameter βL. It then provides solutions for the deflection, slope, bending moment and shear force of an infinite beam under a point load. The document also discusses beams supported by discrete elastic supports and beams subjected to a distributed load segment. It provides examples calculating deflection, bending stress, and pressure for specific beam problems.
Compression members are structural members subjected to axial compression or compressive forces. Their design is governed by strength and buckling capacity. Columns can fail due to local buckling, squashing, overall flexural buckling, or torsional buckling. Built-up columns use components like lacings, battens, and cover plates to help distribute stress more evenly and increase buckling resistance compared to a single member. Buckling occurs when a straight compression member becomes unstable and bends under a critical load.
Calulation of deflection and crack width according to is 456 2000Vikas Mehta
This document discusses the calculation of crack width in reinforced concrete flexural members. It provides information on:
1) Crack width is calculated to satisfy serviceability limits and is only relevant for Type 3 pre-stressed concrete members that crack under service loads.
2) Crack width depends on factors like amount of pre-stress, tensile stress in bars, concrete cover thickness, bar diameter and spacing, member depth and location of neutral axis, bond strength, and concrete tensile strength.
3) The method of calculation involves determining the shortest distance from the surface to a bar and using equations involving member depth, neutral axis depth, average strain at the surface level. Permissible crack widths are specified depending on exposure
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 discusses eccentric connections in bolted joints. There are two types of eccentric connections: 1) where the load acts in the plane of the bolts (Type I) and 2) where the load acts perpendicular to the plane of bolts (Type II). For Type I, the eccentric load can be replaced with a direct shear force and moment force on each bolt. The bolt farthest from the bolt group center and closest to the load bears the maximum force. For Type II, bolts above the neutral axis experience tension and shear while bolts below press against the connected member. Numerical examples calculate forces in bolts for each type of eccentric connection.
The document discusses bolted connections, describing different types of bolts according to material, strength, shear type, fit, pitch, and head shape. It outlines advantages like strength, speed of installation, and easy removal compared to rivets. Disadvantages include reduced strength in axial tension and from loosening under vibration. Types of bolted joints include lap, butt, shop, and field joints. Analysis and design of bolted connections is similar to rivets, accounting for bolt strength based on nominal diameter. Design of bolted shear connections uses laws of friction to calculate load capacity based on number of interfaces and clamping force. An example problem is given to design a doubly bolted lap joint.
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.
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.
Lec11 Continuous Beams and One Way Slabs(1) (Reinforced Concrete Design I & P...Hossam Shafiq II
The document discusses reinforced concrete continuity and analysis methods for continuous beams and one-way slabs. It describes how steel reinforcement must extend through members to provide structural continuity. The ACI/SBC coefficient method of analysis is summarized, which uses coefficient tables to determine maximum shear forces and bending moments for continuous beams and one-way slabs under various loading conditions in a simplified manner compared to elastic analysis. Requirements for applying the coefficient method include having multiple spans with ratios less than 1.2, prismatic member sections, and live loads less than 3 times dead loads.
The document discusses different methods of designing concrete structures, focusing on the limit state method. It describes the limit state method's goal of achieving an acceptable probability that a structure will not become unsuitable for its intended use during its lifetime. The document then discusses stress-strain curves for concrete and steel. It covers stress block parameters and equations for calculating the depth of the neutral axis and moment of resistance for singly reinforced concrete beams. The document concludes by providing examples of analyzing an existing beam section and designing a new beam section.
Because of torsion, the beam fails in diagonal tension forming the spiral cracks around the beam. Warping of the section does not allow a plane section to remain as plane after twisting. Clause 41 of IS 456:2000 provides the provisions for
the design of torsional reinforcements. The design rules for torsion are based on the equivalent moment.
Design of Beam- RCC Singly Reinforced BeamSHAZEBALIKHAN1
Concrete beams are an essential part of civil structures. Learn the design basis, calculations for sizing, tension reinforcement, and shear reinforcement for a concrete beam.
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.
The document discusses machine foundations used in the oil and gas industry. It begins by introducing the different types of machines, such as centrifugal and reciprocating machines, and how they are classified based on speed. It then discusses the various types of foundations used to support these machines, including block foundations and frame foundations. The document outlines the inputs needed for foundation design, which include project specifications, soil parameters, and machine details from the vendor. It describes the process of analyzing machine foundations, including dynamic and static analyses. Key aspects like natural frequencies, displacements, and strength are evaluated.
The document provides a summary of modeling and analyzing slabs in ETABS, including:
1) Common assumptions made in slab modeling such as element type, meshing, shape, and acceptable error.
2) Steps for initial analysis including sketching expected results and comparing total loads.
3) Formulas and coefficients for calculating maximum bending moments in one-way and two-way slabs.
4) A process for designing solid slabs according to Eurocode 2 involving determining reinforcement ratios and areas.
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
This document discusses the analysis and design of reinforced concrete footings. It describes different types of footings including isolated, combined, continuous, and raft foundations. It also covers design considerations such as minimum thickness, concrete cover, reinforcement sizes and spacing, and critical sections. An example is provided to demonstrate the step-by-step design of an isolated square footing, calculating loads, sizing the footing, checking effective depth, determining steel requirements, and verifying hook and dowel bar needs.
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.
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 document discusses beams supported on an elastic foundation. It begins by introducing the Winkler foundation model and defining short, medium, and long beams based on the parameter βL. It then provides solutions for the deflection, slope, bending moment and shear force of an infinite beam under a point load. The document also discusses beams supported by discrete elastic supports and beams subjected to a distributed load segment. It provides examples calculating deflection, bending stress, and pressure for specific beam problems.
Compression members are structural members subjected to axial compression or compressive forces. Their design is governed by strength and buckling capacity. Columns can fail due to local buckling, squashing, overall flexural buckling, or torsional buckling. Built-up columns use components like lacings, battens, and cover plates to help distribute stress more evenly and increase buckling resistance compared to a single member. Buckling occurs when a straight compression member becomes unstable and bends under a critical load.
Calulation of deflection and crack width according to is 456 2000Vikas Mehta
This document discusses the calculation of crack width in reinforced concrete flexural members. It provides information on:
1) Crack width is calculated to satisfy serviceability limits and is only relevant for Type 3 pre-stressed concrete members that crack under service loads.
2) Crack width depends on factors like amount of pre-stress, tensile stress in bars, concrete cover thickness, bar diameter and spacing, member depth and location of neutral axis, bond strength, and concrete tensile strength.
3) The method of calculation involves determining the shortest distance from the surface to a bar and using equations involving member depth, neutral axis depth, average strain at the surface level. Permissible crack widths are specified depending on exposure
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 discusses eccentric connections in bolted joints. There are two types of eccentric connections: 1) where the load acts in the plane of the bolts (Type I) and 2) where the load acts perpendicular to the plane of bolts (Type II). For Type I, the eccentric load can be replaced with a direct shear force and moment force on each bolt. The bolt farthest from the bolt group center and closest to the load bears the maximum force. For Type II, bolts above the neutral axis experience tension and shear while bolts below press against the connected member. Numerical examples calculate forces in bolts for each type of eccentric connection.
The document discusses bolted connections, describing different types of bolts according to material, strength, shear type, fit, pitch, and head shape. It outlines advantages like strength, speed of installation, and easy removal compared to rivets. Disadvantages include reduced strength in axial tension and from loosening under vibration. Types of bolted joints include lap, butt, shop, and field joints. Analysis and design of bolted connections is similar to rivets, accounting for bolt strength based on nominal diameter. Design of bolted shear connections uses laws of friction to calculate load capacity based on number of interfaces and clamping force. An example problem is given to design a doubly bolted lap joint.
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.
This document provides an overview of bending and placing reinforcing steel (rebar) in concrete construction. It describes how rebar is bent to accommodate structural stresses and increase the tensile strength of concrete. Common rebar bends are shown, along with guidelines for minimum bend diameters. Tools for cutting and bending rebar in the field are also discussed, including leverage bars, manual benders, and electric/hydraulic tools.
This presentation is on design of welded and riveted connections in steel structures. in this presentation we learn briefly about these connections and design terminology about these connections.
This document discusses prying action in bolted steel connections. Prying action occurs when the deformation of connected elements under tension increases the tensile force in bolts. It is affected by the strength and stiffness of the connection. The document outlines how to design for prying action by ensuring sufficient bolt diameter, fitting thickness, and distance between bolts. It provides examples calculating the required thickness to prevent prying action. It concludes that prying forces should be considered in design and sufficient rigidity of connected elements is most important.
The document discusses design requirements for bolted and welded structural connections. Key points include:
1) Connections must be designed for both strength and serviceability limit states. Slip-critical bolted connections resist shear through friction and must not slip under service loads.
2) Bolted connections can be designed as either slip-critical or bearing-type depending on loading conditions. Slip-critical connections rely on pretensioned bolts while bearing connections transmit load through bolt bearing and shear strength.
3) Proper bolt pretension, hole size, edge and end distances must be provided to develop the full strength of slip-critical and bearing-type bolted connections. Weld quality is important for
The document discusses design requirements for bolted and welded structural connections. Key points include:
1) Connections must be designed for both strength and serviceability limit states. Slip-critical bolted connections resist shear through friction and must not slip under service loads.
2) Bolted connections can be designed as either slip-critical or bearing-type depending on loading conditions. Slip-critical connections rely on pretensioned bolts while bearing connections transmit load through bolt bearing and shear strength.
3) Proper bolt pretension, hole size, edge and end distances must be considered for bolted connection design according to specifications. Welded connections require quality control due to potential subsurface defects.
The document discusses design considerations for bolted and welded connections. For bolted connections, it describes requirements for slip-critical and bearing-type bolted connections. It provides equations for calculating the nominal shear and bearing resistances of bolts. For welded connections, it describes fillet and groove welds. It provides the equation for calculating the shear strength of a fillet weld and notes limitations on weld sizes.
IRJET - A Review on Steel Beam-Column Joint to Improve the Performance of...IRJET Journal
This document reviews steel beam-column joint connections to improve building performance. It discusses different types of connections including welded moment connections, bolted end-plate moment connections, and shear connections. It also reviews literature on reduced beam section connections, which weaken the beam near the column to localize deformation. Finite element analysis and experiments show that reduced beam section connections provide highly ductile behavior without fractures or distress, improving seismic performance.
This document discusses steel structure connections. It explains that connections are critical and failures often occur due to poor connection design rather than structural member failures. Modern connections use welding or bolting. Bolting has replaced riveting due to being faster and safer to install. Connections are categorized by their loading type, and failure can occur through fasteners or connected parts. Bolted shear connections can fail via fastener shear or bearing on connected materials. Design considers various failure modes.
This document discusses the design of tension members according to IS 800-2007. It defines tension members as structural elements subjected to direct axial tensile loads. Tension members can fail due to gross section yielding, net section rupture, or block shear failure. The document describes various types of tension members including wires, bars, plates, structural shapes, and their behavior under tensile loads. It provides equations to calculate the design strength based on the different failure modes and discusses factors like slenderness ratio and shear lag that influence tension member design. Numerical examples are given to illustrate the design strength calculations.
System shear connector digunakan sebagai aplikasi dalam konstruksi bangunan untuk menghasilkan kekuatan coran beton lebih kuat dan stabil sesuai dengan perhitungan engineering civil. Dalam hal ini ada 2 hal perhitungan kekuatan secara umum yaitu kekuatan kelengketan stud pada batang baja sesudah dilas. Dan yang kedua adalah kekuatan stud bolt yang digunakan.
The document discusses the design of bolted and welded structural connections. It covers topics such as:
1) Connections must be designed for strength limit states and be symmetrical about member axes.
2) Slip-critical bolted connections resist shear through pre-tensioned bolts generating friction, while bearing connections transmit load through bolt bearing and shear.
3) Design of bolted connections involves checking the nominal shear and bearing resistances of bolts and connected materials against factored loads.
The document discusses bolted connections. It begins by explaining that all components of a bolted connection must be verified, including shear resistance of the beam web, compression resistance of the beam web, tension resistance of the beam web, bending resistance of the beam flanges, bending resistance of the cover plate, and compression resistance of the beam flange and web. It then describes the different potential failure modes for bolted connections, including failure due to crushing of the plate material in the bolt holes, shear failure, tension failure of the connected plates, tension failure of the bolt, and combined shear and tension failure. Finally, it provides tables summarizing classification of bolted connection categories according to how the bolts are loaded, as well as
Tension members are structural elements subjected to direct tensile loads. Their strength depends on factors like length of connection, size and spacing of fasteners, cross-sectional area, fabrication type, connection eccentricity, and shear lag. Failure can occur through gross section yielding, net section rupture, or block shear. Design involves selecting a member with sufficient gross area to resist factored loads in yielding, then checking strength considering net section rupture and block shear failure modes.
1. The document discusses the design of various welded joints, including butt joints, transverse and parallel fillet joints, and circular fillet joints subjected to torsion. It provides the equations to calculate the permissible load or torque based on the weld material properties and joint geometry.
2. Examples of design calculations are provided for parallel fillet joints subjected to load and transverse fillet joints. Design stresses for welds using bare and covered electrodes are also tabulated.
3. Review questions at the end test the understanding of welded joint design, and examples are worked out for fillet joints subjected to load and a circular fillet joint subjected to torque.
Machine Design and Industrial Drafting.pptxNilesh839639
This document discusses various types of shaft couplings, including:
- Sleeve or muff couplings, which consist of a hollow sleeve that slides over the shaft ends. Rigid couplings like clamp couplings work similarly but the sleeve is split into halves.
- Flange couplings have two separate cast iron flanges mounted on each shaft and bolted together. Marine flange couplings have the flanges forged integrally with the shafts.
- Flexible couplings like bushed-pin couplings allow some misalignment of the connected shafts using rubber or leather bushes over the coupling bolts. Oldham and universal couplings can accommodate other types of shaft misalignment.
The document provides design procedures and equations for determining
IRJET- Analysis of Hot Rolled Steel Angles Under TensionIRJET Journal
This document analyzes the block shear capacity and failure mechanisms of hot rolled steel angles used as tension members. It discusses the design strengths according to yielding of the gross section, rupture of the critical section, and block shear. Block shear is a failure that combines tensile rupture on one plane and shear yield or rupture on a perpendicular plane. The document outlines the methodology used to test steel angle specimens in a Universal Testing Machine and compares the results to design equations in the Indian code IS 800:2007. It was found that the limit state method provides more accurate design strengths and is more economical than other methods. Testing confirmed that locally available steel angles meet code criteria.
1. The document discusses different types of joints used to connect structural components including knuckle joints, welded joints, and fillet joints.
2. Knuckle joints provide flexibility and angular movement, while welded joints create a permanent connection through fusion. Fillet joints are made by overlapping plates and welding their edges.
3. The document provides equations to calculate the strength of various welded and fillet joint configurations based on the load applied and permissible stress levels. Examples are given of calculating weld sizes for different joint geometries under static and fatigue loading conditions.
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Bolted connections
1. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
CHAPTER 5. BOLTED CONNECTION
5.1 INTRODUCTORY CONCEPTS
• There are different types of bolted connections. They can be categorized based on the type of
loading.
- Tension member connection and splice. It subjects the bolts to forces that tend to shear
the shank.
- Beam end simple connection. It subjects the bolts to forces that tend to shear the shank.
- Hanger connection. The hanger connection puts the bolts in tension
1
2. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
• The bolts are subjected to shear or tension loading.
- In most bolted connection, the bolts are subjected to shear.
- Bolts can fail in shear or in tension.
- You can calculate the shear strength or the tensile strength of a bolt
• Simple connection: If the line of action of the force acting on the connection passes through
the center of gravity of the connection, then each bolt can be assumed to resist an equal share
of the load.
• The strength of the simple connection will be equal to the sum of the strengths of the
individual bolts in the connection.
• We will first concentrate on bolted shear connections.
2
3. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
5.2 BOLTED SHEAR CONNECTIONS
• We want to design the bolted shear connections so that the factored design strength (φ Rn) is
greater than or equal to the factored load.
• So, we need to examine the various possible failure modes and calculate the corresponding
design strengths.
• Possible failure modes are:
- Shear failure of the bolts
- Failure of member being connected due to fracture or block shear or ….
- Edge tearing or fracture of the connected plate
- Tearing or fracture of the connected plate between two bolt holes
- Excessive bearing deformation at the bolt hole
• Shear failure of bolts
- Average shearing stress in the bolt = fv = P/A = P/(π db
2
/4)
- P is the load acting on an individual bolt
- A is the area of the bolt and db is its diameter
- Strength of the bolt = P = fv x (π db
2
/4) where fv = shear yield stress = 0.6Fy
- Bolts can be in single shear or double shear as shown below.
- When the bolt is in double shear, two cross-sections are effective in resisting the load.
The bolt in double shear will have the twice the shear strength of a bolt in single shear.
3
4. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
• Failure of connected member
- We have covered this in detail in Ch. 2 on tension members
- Member can fail due to tension fracture or block shear.
• Bearing failure of connected/connecting part due to bearing from bolt holes
- Hole is slightly larger than the fastener and the fastener is loosely placed in hole
- Contact between the fastener and the connected part over approximately half the
circumference of the fastener
- As such the stress will be highest at the radial contact point (A). However, the average
stress can be calculated as the applied force divided by the projected area of contact
- Average bearing stress fp = P/(db t), where P is the force applied to the fastener.
- The bearing stress state can be complicated by the presence of nearby bolt or edge. The
bolt spacing and edge distance will have an effect on the bearing str.
- Bearing stress effects are independent of the bolt type because the bearing stress acts on
the connected plate not the bolt.
4
5. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
- A possible failure mode resulting from excessive bearing close to the edge of the
connected element is shear tear-out as shown below. This type of shear tear-out can also
occur between two holes in the direction of the bearing load.
Rn = 2 x 0.6 Fu Lc t = 1.2 Fu Lc t
5
6. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
- To prevent excessive deformation of the hole, an upper limit is placed on the bearing
load. This upper limit is proportional to the fracture stress times the projected bearing
area
Rn = C x Fu x bearing area = C Fu db t
If deformation is not a concern then C = 3, If deformation is a concern then C=2.4
C = 2.4 corresponds to a deformation of 0.25 in.
- Finally, the equation for the bearing strength of a single bolts is φRn
where, φ = 0.75 and Rn = 1.2 Lc t Fu < 2.4 db t Fu
Lc is the clear distance in the load direction, from the edge of the bolt hole to the edge of
the adjacent hole or to the edge of the material
- This relationship can be simplified as follows:
The upper limit will become effective when 1.2 Lc t Fu = 2.4 db t Fu
i.e., the upper limit will become effective when Lc = 2 db
If Lc < 2 db, Rn = 1.2 Lc t Fu
If Lc > 2 db, Rn = 1.4 db t Fu
6
7. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
5.3 DESIGN PROVISIONS FOR BOLTED SHEAR CONNECTIONS
• In a simple connection, all bolts share the load equally.
T
T
T/n T/n
T/n T/n
T/n T/n
T
T
T/n T/n
T/n T/n
T/n T/n
• In a bolted shear connection, the bolts are subjected to shear and the connecting / connected
plates are subjected to bearing stresses.
Bolt in shear
Bearing stresses in plate
Bearing stresses in plate
T
T
T
T
Bolt in shear
Bearing stresses in plate
Bearing stresses in plate
Bolt in shear
Bearing stresses in plate
Bearing stresses in plate
T
T
T
T
• The shear strength of all bolts = shear strength of one bolt x number of bolts
• The bearing strength of the connecting / connected plates can be calculated using equations
given by AISC specifications.
• The tension strength of the connecting / connected plates can be calculated as discussed
earlier in Chapter 2.
5.3.1 AISC Design Provisions
• Chapter J of the AISC Specifications focuses on connections.
• Section J3 focuses on bolts and threaded parts
7
8. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
• AISC Specification J3.3 indicates that the minimum distance (s) between the centers of bolt
holes is 2 bd
3
2
. A distance of 3db is preferred.
• AISC Specification J3.4 indicates that the minimum edge distance (Le) from the center of the
bolt to the edge of the connected part is given in Table J3.4 on page 16.1-61. Table J3.4
specifies minimum edge distances for sheared edges, edges of rolled shapes, and gas cut
edges.
• AISC Specification J3.5 indicates that the maximum edge distance for bolt holes is 12 times
the thickness of the connected part (but not more than 6 in.). The maximum spacing for bolt
holes is 24 times the thickness of the thinner part (but not more than 12 in.).
• Specification J3.6 indicates that the design tension or shear strength of bolts is φ FnAb
- Table J3.2 gives the values of φ and Fn
- Ab is the unthreaded area of bolt.
- In Table J3.2, there are different types of bolts A325 and A490.
- The shear strength of the bolts depends on whether threads are included or excluded from
the shear planes. If threads are included in the shear planes then the strength is lower.
- We will always assume that threads are included in the shear plane, therefore less
strength to be conservative.
• We will look at specifications J3.7 – J3.9 later.
• AISC Specification J3.10 indicates the bearing strength of plates at bolt holes.
- The design bearing strength at bolt holes is φRn
- Rn = 1.2 Lc t Fu ≤ 2.4 db t Fu - deformation at the bolt holes is a
design consideration
- Where, Fu = specified tensile strength of the connected material
8
9. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
- Lc = clear distance, in the direction of the force, between the edge of the hole and the
edge of the adjacent hole or edge of the material (in.).
- t = thickness of connected material
5.3.2 AISC Design Tables
• Table 7-10 on page 7-33 of the AISC Manual gives the design shear of one bolt. Different
bolt types (A325, A490), thread condition (included or excluded), loading type (single shear
or double shear), and bolt diameters (5/8 in. to 1-1/2 in.) are included in the Table.
• Table 7-11 on page 7-33 of the AISC Manual is an extension of Table 7-10 with the
exception that it gives the shear strength of ‘n’ bolts.
• Table 7-12 on page 7-34 of the AISC manual gives the design bearing strength at bolt holes
for various bolt spacings.
- These design bearing strengths are in kips/in. thickness.
- The tabulated numbers must be multiplied by the plate thickness to calculate the design
bearing strength of the plate.
- The design bearing strengths are given for different bolt spacings (2.67db and 3db),
different Fu (58 and 65 ksi), and different bolt diameters (5/8 – 1-1/2 in.)
- Table 7-12 also includes the spacing (sfull) required to develop the full bearing strength
for different Fu and bolt diameters
- Table 7-12 also includes the bearing strength when s > sfull
- Table 7-12 also includes the minimum spacing 2-2/3 db values
• Table 7-13 in the AISC manual on page 7-35 is similar to Table 7-12. It gives the design
bearing strength at bolt holes for various edge distances.
9
10. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
- These design bearing strengths are in kips/in. thickness.
- The tabulated numbers must be multiplied by the plate thickness to calculate the design
bearing strength of the plate.
- The design bearing strengths are given for different edge distances (1.25 in. and 2 in.),
different Fu (58 and 65 ksi), and different bolt diameters (5/8 – 1-1/2 in.)
- Table 7-13 also includes the edge distance (Le full) required to develop the full bearing
strength for different Fu and bolt diameters
- Table 7-13 also includes the bearing strength when Le > Le full
10
11. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
Example 5.1 Calculate and check the design
strength of the connection shown below. Is
the connection adequate for carrying the
factored load of 65 kips.
1.25 2.50 1.25
1.25
2.50
1.25
65 k
A36
A36 5 x ½
3/8 in.
¾ in. bolts
1.25 2.50 1.25
1.25
2.50
1.25
65 k
A36
A36 5 x ½
3/8 in.
¾ in. bolts
Solution
Step I. Shear strength of bolts
• The design shear strength of one bolt in shear = φ Fn Ab = 0.75 x 48 x π x 0.752
/4
- φ Fn Ab = 15.9 kips per bolt (See Table J3.2 and Table 7-10)
- Shear strength of connection = 4 x 15.9 = 63.6 kips (See Table 7-11)
Step II. Minimum edge distance and spacing requirements
• See Table J3.4, minimum edge distance = 1 in. for rolled edges of plates
- The given edge distances (1.25 in.) > 1 in. Therefore, minimum edge distance
requirements are satisfied.
• Minimum spacing = 2.67 db = 2.67 x 0.75 = 2.0 in.
- Preferred spacing = 3.0 db = 3.0 x 0.75 = 2.25 in.
- The given spacing (2.5 in.) > 2.25 in. Therefore, spacing requirements are satisfied.
Step III. Bearing strength at bolt holes.
• Bearing strength at bolt holes in connected part (5 x ½ in. plate)
- At edges, Lc = 1.25 – hole diameter/2 = 1.25 – (3/4 + 1/16)/2 = 0.844 in.
- φRn = 0.75 x (1.2 Lc t Fu) = 0.75 x (1.2 x 0.844 x 0.5 x 58) = 22.02 kips
- But, φRn ≤ 0.75 (2.4 db t Fu) = 0.75 x (2.4 x 0.75 x 0.5 x 58) = 39.15 kips
- Therefore, φRn = 22.02 kips at edge holes
• Compare with value in Table 7-13. φRn = 44.0 x 0.5 = 22.0 kips
11
12. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
- At other holes, s = 2.5 in, Lc = 2.5 – (3/4 +1/16) = 1.688 in.
- φRn = 0.75 x (1.2 Lc t Fu) = 0.75 x (1.2 x 1.688 x 0.5 x 58) = 44.05 kips
- But, φRn ≤ 0.75 (2.4 db t Fu) = 39.15 kips. Therefore φRn = 39.15 kips
- Therefore, φRn = 39.15 kips at other holes
• Compare with value in Table 7-12. φRn = 78.3 x 0.5 =39.15 kips
- Therefore, bearing strength at holes = 2 x 22.02 + 2 x 39.15 = 122.34 kips
• Bearing strength at bolt holes in gusset plate (3/8 in. plate)
- At edges, Lc = 1.25 – hole diameter/2 = 1.25 – (3/4 + 1/16)/2 = 0.844 in.
- φRn = 0.75 x (1.2 Lc t Fu) = 0.75 x (1.2 x 0.844 x 0.375 x 58) = 16.52 k
- But, φRn ≤ 0.75 (2.4 db t Fu) = 0.75 x (2.4 x 0.75 x 0.375 x 58) = 29.36 kips
- Therefore, φRn = 16.52 kips at edge holes
• Compare with value in Table 7-13. φRn = 44.0 x 3/8 = 16.5 kips
- At other holes, s = 2.5 in, Lc = 2.5 – (3/4 +1/16) = 1.688 in.
- φRn = 0.75 x (1.2 Lc t Fu) = 0.75 x (1.2 x 1.688 x 0.375 x 58) = 33.04 kips
- But, φRn ≤ 0.75 (2.4 db t Fu) = 29.36 kips
- Therefore, φRn = 29.36 kips at other holes
• Compare with value in Table 7-12. φRn = 78.3 x 0.375 = 29.36 kips
- Therefore, bearing strength at holes = 2 x 16.52 + 2 x 29.36 = 91.76 kips
• Bearing strength of the connection is the smaller of the bearing strengths = 91.76 kips
12
13. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
Connection Strength
Shear strength = 63.3 kips
Bearing strength (plate) = 122.34 kips
Bearing strength (gusset) = 91.76 kips
Connection strength (φRn) > applied factored loads (γQ). Therefore ok.
13
14. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
Example 5.2 Design a double angle tension member and a gusset plated bolted connection
system to carry a factored load of 100 kips. Assume A36 (36 ksi yield stress) material for the
double angles and the gusset plate. Assume A325 bolts. Note that you have to design the double
angle member sizes, the gusset plate thickness, the bolt diameter, numbers, and spacing.
Solution
Step I. Design and select a trial tension member
• See Table 3-7 on page 3-33 of the AISC manual.
- Select 2L 3 x 2 x 3/8 with φPn = 113 kips (yielding) and 114 kips (fracture)
- While selecting a trial tension member check the fracture strength with the load.
Step II. Select size and number of bolts
The bolts are in double shear for this design (may not be so for other designs)
• See Table 7-11 on page 7-33 in the AISC manual
Use four 3/4 in. A325 bolts in double shear
φRn = 127 kips - shear strength of bolts from Table 7-11
Step III. Design edge distance and bolt spacing
• See Table J3.4
- The minimum edge distance = 1 in. for 3/4 in. diameter bolts in rolled edges.
- Select edge distance = 1.25 in.
• See specification J3.5
- Minimum spacing = 2.67 db = 2.0 in.
- Preferred spacing = 3.0 db = 2.25 in.
- Select spacing = 3.0 in., which is greater than preferred or minimum spacing
14
15. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
Step IV. Check the bearing strength at bolt holes in angles
• Bearing strength at bolt holes in angles
- Angle thickness = 3/8 in.
- See Table 7-13 for the bearing strength per in. thickness at the edge holes
- Bearing strength at the edge holes (Le = 1.25 in.) = φRn = 44.0 x 3/8 = 16.5 k
- See Table 7-12 for the bearing strength per in. thickness at non-edge holes
- Bearing strength at non-edge holes (s = 3 in.) = φRn = 78.3 x 3/8 = 29.4 k
- Bearing strength at bolt holes in each angle = 16.5 + 3 x 29.4 = 104.7 kips
- Bearing strength of double angles = 2 x 104.7 kips = 209.4 kips
Step V. Check the fracture and block shear strength of the tension member
• This has been covered in the chapter on tension members and is left to the students.
Step VI. Design the gusset plate
• See specification J5.2 for designing gusset plates. These plates must be designed for the
limit states of yielding and rupture
- Limit state of yielding
o φRn = 0.9 Ag Fy > 100 kips
o Therefore, Ag = L x t > 3.09 in2
o Assume t = ½ in; Therefore L > 6.18 in.
o Design gusset plate = 6.5 x ½ in.
o Yield strength = φRn = 0.9 x 6.5 x 0.5 x 36 = 105.3 kips
- Limit state for fracture
15
16. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
o An = Ag – (db+1/8) x t
o An = 6.5 x 0.5 – (3/4 + 1/8) x 0.5 = 2.81 in2
o But, An ≤ 0.85 Ag = 0.85 x 3.25 = 2.76 in2
o φRn = 0.75 x An x Fu = 0.75 x 2.76 x 58 = 120 kips
- Design gusset plate = 6.5 x 0.5 in.
• Step VII. Bearing strength at bolt holes in gusset plates
Assume Le = 1.25 in. (same as double angles)
- Plate thickness = 3/8 in.
- Bearing strength at the edge holes = φRn = 44.0 x 1/2 = 22.0 k
- Bearing strength at non-edge holes = φRn = 78.3 x 1/2 = 39.15 k
- Bearing strength at bolt holes in gusset plate = 22.0 + 3 x 39.15 = 139.5 kips
Summary of Member and Connection Strength
Connection Member Gusset Plate
Shear strength = 127 kips Yielding = 113 kips Yielding = 105.3 kips
Bearing strength = 209.4 kips (angles) Fracture = ? Fracture = 120 kips
Bearing Strength = 139.5 (gusset) Block Shear = ?
- Overall Strength is the smallest of all these numbers = 105.3 kips
- Gusset plate yielding controls
- Resistance > Factored Load (100 kips).
- Design is acceptable
16
17. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
5.4 SLIP-CRITICAL BOLTED CONNECTIONS
• High strength (A325 and A490) bolts can be installed with such a degree of tightness that
they are subject to large tensile forces.
• These large tensile forces in the bolt clamp the connected plates together. The shear force
applied to such a tightened connection will be resisted by friction as shown in the Figure
below.
Tightened
P
P
TightenedTightened
P
P
P
P
Tb
N =Tb
N =Tb
N =Tb
P
F=µN
Tb
N = Tb
F=µN
N = Tb
N =Tb
P
Tb
N =Tb
Tb
N =Tb
N =Tb
N =Tb
P
F=µN
N =Tb
N =Tb
P
F=µN
Tb
N = Tb
Tb
N = Tb
F=µN
N = Tb
N =Tb
P
F=µN
N = Tb
N =Tb
N = Tb
N =Tb
P
• Thus, slip-critical bolted connections can be designed to resist the applied shear forces using
friction. If the applied shear force is less than the friction that develops between the two
surfaces, then no slip will occur between them.
• However, slip will occur when the friction force is less than the applied shear force. After
slip occurs, the connection will behave similar to the bearing-type bolted connections
designed earlier.
17
18. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
• Table J3.1 summarizes the minimum bolt tension that must be applied to develop a slip-
critical connection.
• The shear resistance of fully tensioned bolts to slip at factored loads is given by AISC
Specification J3.8 a
Shear resistance at factored load = φRn = 1.13 µ Tb Ns
where, φ = 1.0 for standard holes
µ = 0.33 (Class A surface with unpainted clean mill scale surface: CE 405)
Tb = minimum bolt tension given in Table J3.1
Ns = number of slip planes
- See Table 7-15 on page 7-36 of the AISC manual. This Table gives the shear resistance
of fully tensioned bolts to slip at factored loads on class A surfaces.
- For example, the shear resistance of 1-1/8 in. bolt fully tensioned to 56 kips (Table J3.1)
is equal to 20.9 kips (Class A faying surface).
- When the applied shear force exceeds the φRn value stated above, slip will occur in the
connection.
• The shear resistance of fully tensioned bolts to slip at service loads is given by AISC
Specification J3.8 b.
- Shear resistance at service load = φRn = φ Fv Ab
- Where, φ = 1.0 for standard holes
Fv = slip-critical resistance to shear at service loads, see Table A-J3.2 on
page 16.1-116 of the AISC manual
- See Table 7-16 on page 7-37 of the AISC manual. This Table gives the shear resistance
of fully tensioned bolts to slip at service loads on class A surfaces.
18
19. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
- For example, the shear resistance of 1-1/8 in. bolt fully tensioned to 56 kips (Table J3.1)
is equal to 16.9 kips (Class A faying surface).
- When the applied shear force exceeds the φRn value stated above, slip will occur in the
connection.
• The final strength of the connection will depend on the shear strength of the bolts calculated
using the values in Table 7-11 and on the bearing strength of the bolts calculated using the
values in Table 7-12, 7-13. This is the same strength as that of a bearing type connection.
19
20. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
Example 5.3 Design a slip-critical splice for a tension member subjected to 300 kips of tension
loading. The tension member is a W8 x 28 section made from A992 (50 ksi) material. The
unfactored dead load is equal to 50 kips and the unfactored live load is equal to 150 kips. Use
A325 bolts. The splice should be slip-critical at service loads.
Solution
Step I. Service and factored loads
• Service Load = D + L = 200 kips.
• Factored design load = 1.2 D + 1.6 L = 300 kips
• Tension member is W8 x 28 section made from A992 (50 ksi) steel. The tension splice must
be slip critical (i.e., it must not slip) at service loads.
Step II. Slip-critical splice connection
• φRn of one fully-tensioned slip-critical bolt = φ Fv Ab (See Spec. A-J3.8 b)
page 16.1-117 of AISC
• If db = 3/4 in.
φRn of one bolt = 1.0 x 17 x π x 0.752
/4 = 7.51 kips
Note, Fv = 17 ksi from Table A-J3.2
From Table 7-16 on page 7-37 φRn = 7.51 kips
φRn of n bolts = 7.51 x n > 200 kips (splice must be slip-critical at service)
Therefore, n > 26.63
• If db = 7/8 in.
φRn of one bolt = 10.2 kips -from Table 7-16
φRn of n bolts = 10.2 x n > 200 kips (splice must be slip-critical at service)
Therefore, n > 19.6 bolts
20
21. Number of bolts required n
Ps
φRn
:= n 26.63= (min. reqd.)
If diameter of the bolt =• db
7
8
:= in Ab
π
4
db( )2
:=
for one bolt φRn φ Fv⋅ Ab⋅:= φRn 10.222= Kips
Number of bolts required n
Ps
φRn
:= n 19.565= (min. reqd.)
say we provide 24 bolts on either side of the center line, 6 on either side of the flanges, top + bottom
Step III: Connection Details and spacings for 24 bolts on each W8 x 28
Note that there are 24 bolts on either side of the center line. In all there are 48 number - 7/8 in dia bolts•
used in the connection.
Minimum pretension applied to the bolts = 39.0 Kips from Table J3.1•
Minimum Edge distance from Table J3.4 = Le-min = 1.125 in•
Provide Edge Distance =• Le 1.25:= in
Minimum spacing (Spec. J3.3) =• s 2.67 db⋅:= s 2.336= in
Example 5.3
Step I: Service and Factored Loads
D 50:= Kips L 150:= Kips
Service Loads• Ps D L+:= Ps 200= Kips
Factored Loads• Pu 1.2 D⋅ 1.6 L⋅+:= Pu 300= Kips
Step II: Slip Critical connection
In Service loads consideration, φRn of one fully tenstioned slip-critical bolt = φ Fv Ab•
(As given in Spec. A-J3.8b - page 16.1-117) φ 1.0:= Fv 17:= Ksi - A325 - Table A-J3.2
If diameter of the bolt =• db
3
4
:= in Ab
π
4
db( )2
:=
for one bolt φRn φ Fv⋅ Ab⋅:= φRn 7.51= Kips
22. KipsPu 300=KsiFu 65:=KsiFy 50:=Step V: Design the splice plate
KipsBt 2.223 10
3
×=
Bt 4 Be⋅ 20 Bo⋅+:=Total bearing strength of the bolt holes in wide flange section•
Table 7-12Kip / in thicknessBo 102:=Bearing strength of 7/8 in. bolt at other holes =•
Table 7-13
Preferred spacing = s 3 db⋅:= s 2.625= in
From table 7-12 sfull 2.6875:= in
For design provide spacing = s 3:= in
Step IV: Connection Strength at factored loads
The splice connection should be designed as a normal shear / bearing connection beyong this point for the•
factored load = 300 kips
The shear strength of the bolts (Table 7-10) = 21.6 kips/bolt x 24 bolts = 518.4 Kips•
Bearing strength of 7/8 in. bolt at edge holes =• Be 45.7:= Kip / in thickness
23. Ag b t⋅:= Ag 16.35= in
2
> minAg 6.667= in
2
An Ag 4
7
8
1
8
+⎛
⎜
⎝
⎞
⎠
⋅ t⋅−:= An 6.35= in
2
> minAn 6.154= in
2
Check An 6.35= in
2
< 0.85 Ag⋅ 13.898= in
2
Strength of the splice plate in•
yielding = 0.9 Ag⋅ Fy⋅ 735.75= Kips
> Pu 300= Kips
fracture = 0.75 An⋅ Fu⋅ 309.563= Kips
Check for bearing strength of the splice plates•
Check for block shear rupture•
Step VI : Check member yield, fracture and block shear....
Tension Yielding = 0.9 Ag Fy > Pu• minAg
Pu
0.9 Fy⋅
:= minAg 6.667= in
2
Tension Fracture = 0.75 An Fu > Pu• minAn
Pu
0.75 Fu⋅
:= minAn 6.154= in
2
We know, flange width of W 8 x 28 = 6.54 in. This is the limiting width of the splice plate. The unknown
quantity which is the thickness of each splice plate is calculated as shown.
Net area = Gross area - area of the bolts An minAn:=
An Ag 4
7
8
1
8
+⎛
⎜
⎝
⎞
⎠
⋅ t⋅−:= Ag Here, Ag 6.54 t⋅:= t An 6.154:= in
2
Check for An and Ag:
intmin 2.42=>int 2.5=t 2 tp⋅:=therefore, total plate thickness =
intp 1.25:=inb 6.54:=Assume each plate of the dimensions
(This is the total thickness of the plate at the top and bottom)intmin 2.42:=Solving for t, we get
24. CE 405: Design of Steel Structures – Prof. Dr. A. Varma
Example 4.4 Modify Example 4.2 so that the connection system is slip critical for the factored
load of 100 kips.
Solution
Step I. Design and select a trial tension member (same as example 4.2)
• Select 2L 3 x 2 x 3/8 with φPn = 113 kips (yielding) and 114 kips (fracture)
Step II. Select size and number of bolts (modified step)
• The connection must be designed to be slip-critical at the factored loads
- φRn for one bolt = 1.0 x 1.13 x µ x Tb x Ns (Tb from Table J3.1)
- φRn for one 3/4 in. bolt = 1.0 x 1.13 x 0.33 x 28 x 2 = 20.9 kips
- φRn for one 7/8 in. bolt = 1.0 x 1.13 x 0.33 x 39 x 2 = 29.1 kips
- See Values in Table 7-15.
φRn for ¾ and 7/8 in. bolts in double slip = 20.9 and 29.1 kips, respectively.
- We need at least five ¾ in. bolts to have strength φRn = 5 x 20.9 = 104.5 k > 100 k
- We need at least four 7/8 in. bolts to have strength φRn = 4 x 29.1 = 116.4 k> 100
• Use five ¾ in. fully tightened bolts. Bolts must be tightened to 28 kips.
• Compare with solution for example 4.2 where only four snug-tight ¾ in bolts design.
For the remaining steps III to VII follow Example 4.2
Step III. Design edge distance and bolt spacing
Step IV. Check the bearing strength at bolt holes in angles
Step V. Check the fracture and block shear strength of the tension member
Step VI. Design the gusset plate
Step VII. Bearing strength at bolt holes in gusset plates
Summary of Member and Connection Strength
23