High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction AISC Live Webinars AISC Live Webinars Thank you for joining our live webinar today. We will begin shortly. Please standby. Need Help? Call ReadyTalk Support: 800.843.9166 Today’s audio will be broadcast through the internet. Alternatively, to hear the audio through the phone, dial 800.952.4629. 800.952.4629. International callers, dial 00+1+212.231.2934. For additional support, please press *0 and you will be connected to a live operator. There’s always a solution in steel. There’s always a solution in steel. AISC Live Webinars High-Strength Bolts: The Basics Thank you. Today’s live webinar will begin shortly. Please standby. As a reminder, all lines have been muted. Please type any questions or comments through the Chat feature on the left portion of your screen. Presented by Geoff Kulak, Ph.D. Professor Emeritus at the University of Alberta Today’s audio will be broadcast through the internet. Alternatively, to hear the audio through the phone, dial 800.952.4629. 800.952.4629. International callers, dial 00+1+212.231.2934. For additional support, please press *0 and you will be connected to a live operator. There’s always a solution in steel. There's always a solution in steel. There’s always a solution in steel. 1 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction High-Strength Bolts: The Basics • Fundamentals and Behavior • Specification Requirements (AISC 2010) Role of the Structural Engineer… • Selection of suitable bolt types and grades • • • Design of the fasteners Responsibility for installation Responsibility for inspection 5 ASTM A307 Bolts ASTM A325 Bolts • Type 1 or Type 3 (weathering steel) • often a good choice when loads are static • ASTM Spec. • strength level inferior to high- RCSC Spec. • Minimum tensile strength: 120 ksi strength bolts (60 ksi tensile ult.) • Pretension can be induced if desired • pretension indeterminate 7 There's always a solution in steel. 6 8 2 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Comparison of Bolts: Direct Tension ASTM A490 Bolts • • 80 Types 1 or Type 3 (weathering steel) Minimum tensile strength: 150 ksi, bolt tension kips (maximum 170 ksi) RCSC Spec. • ASTM Spec. • Pretension can be induced if desired 7/8 in. dia. A490 bolt 60 7/8 in. dia. A325 bolt 40 7/8 in. dia. A307 bolt 20 0.05 0.10 0.15 0.20 elongation (inches) 9 …comments cont’d Comments… • Nuts: ASTM A563 • Washers: if needed, ASTM F436 • Note: we quote the ultimate tensile strength of the bolt – benchmark for strength statements (e.g. shear strength is some fraction of ultimate tensile strength) • Bolt – nut – washer sets implied so far, but other configurations available • Bolt notation: Group A (A325, F1852) • What about yield strength? • What is “proof load” and Group B (A490, F2280) 11 There's always a solution in steel. 10 12 3 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Loading of Bolts Shear Loading • Shear – load transfer by shear in bolt and bearing in connected material OR – load transfer by friction (followed by shear and bearing) • Tension • Combined Tension and Shear Truss Joint 13 14 Bolts in Tension – prying Bolts Loaded in Tension Prying force Bolt force bolts in tension Applied force these bolts in shear HighHigh-strength bolts in tension can be a source of problems 15 There's always a solution in steel. 16 4 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Bolts in combined tension and shear bolts in combined shear and tension bolts in shear Consider a simple joint — P P 17 18 Finally... P P{ and associated shear stress τ= d P A P/2 Free body of bolt P { a bearing force P 19 There's always a solution in steel. t P P/2 this force is equal and opposite to the bearing force shown previously 20 5 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction In the example, we identified… AISC Standard 2010 • Parallel LRFD and ASD rules • force in the bolt (a shear force) • LRFD uses a resistance factor, Ø • force that the bolt imposed on the plate (a bearing force) • ASD uses a safety factor, Ω • Loads as appropriate: • force in the plate itself (a tensile force) – factored loads for LRFD – non-factored loads for ASD • force transfer could also be by friction: friction: not included in this illustration 21 Installation — AISC Specification cont’d LRFD: req’d strength LRFD ≤ φ R n ASD: req’d strength ASD ≤ R n / Ω 22 • SnugSnug-tight only • Pretensioned – Calibrated wrench – TurnTurn-ofof-nut – Other means: Tension control bolts LoadLoad-indicator washers 23 There's always a solution in steel. 24 6 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Behavior of a large joint (shear splice) — Bolts in Shear: Issues • Shear strength of bolt (single shear or double shear, threads in shear plane?) average bolt shear • Bearing capacity of bolt (never MPa governs) • Bearing capacity of plate • Tensile (comp.) capacity of plate deformation over α , mm 25 26 Bolts in shear-type connections: Slip in bolted joints… • Can be as much as two hole Specifications include information for: clearances • Some bolts will already be in bearing at start of loading – bearing type connections – slipslip-critical connections • Both laboratory tests and field measurements indicate that slip is more like 1/2 hole clearance 27 There's always a solution in steel. 28 7 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Bearing-type connections: Bolts in bearing-type connections… • Issues Region of bearingbearingtype behavior load – bolt shear strength – bearing capacity of connected material – member strength • Shear strength of bolts is not dependent on presence or absence of pretension. pretension (How come?) deformation 29 30 Individual bolt in shear Bolt Shear Strength • Bolt shear strength ≈ 62% of bolt ultimate tensile strength (theory (theory + tests) tests) – Design rule takes 90% of this value – Threads in shear plane? – Long joint effect: another discount applied. 31 There's always a solution in steel. 32 8 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Physical test — Uneven loading of bolts – (End four bolts of 13) 33 34 Back to bolt in shear — Bolt Pretension v. Shear • The bolt pretension is attained as a result of small axial elongations introduced as nut is turned on • These small elongations are relieved as shear deformations and shear yielding take place Shear strength of single bolt (tests) — τ = 0.62 σ u bolt • Confirmed by both bolt tension measurements and shear strength tests • So, bolt shear strength NOT dependent on pretension in the bolt. Shear deformation 35 There's always a solution in steel. 36 9 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Bolts in Shear — AISC nominal shear strength … φ R n = φ Fnv A b Fnv = 90% (0.625 × Fu ) = 0.563 Fu φ R n = design shear strength Fnv = nominal shear strength, ksi e.g. A325 bolt, no threads in shear plane , Group A : see tabulated value in Table J3.2 (0.563 ksi Fu = 0.563 x 120 ksi = 68 ksi) 37 38 Comments… and… • The discount for length (use of 90%) is For threads included, the tabulated values are 80% of the above. • If joint length > 38 in., a further reduction, conservative to 83% • The ø – value used for this case (0.75) is conservative 39 There's always a solution in steel. 40 10 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Let’s return now to slip-critical connections… Slip-Critical Connection Clamping force from bolts (bolt pretension) Load at which slip takes place will be a function of …? 42 Bolts in slip-critical connections… Slip-critical joints specified when… • Load is repetitive and changes from tension to compression (fatigue by fretting could occur.) load • Change in geometry of structure would affect its performance. region of slipslip-critical joint behavior critical joints should be the exception, not the rule (but, see also seismic rules) deformation 43 There's always a solution in steel. • Certain other cases. • Comment: Comment: for buildings, slipslip- 44 11 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction First principles, slip resistance is — Design slip resistance, AISC R n = μ D u h f Tb n s P = ks n ΣTi ks = slip coefficient (µ) n = number of slip planes (usually 1 or 2) Ti = clamping force (i.e., bolt pretension) slip coefficient no. slip planes clamping force …terms hf and Du need to be defined and a value inserted for Ø 45 and the modifiers … 46 A note for advanced readers!! h f = modifier re fills : either 1.0 or 0.85 φ = 1.0 for std. holes and for short slots ⊥ Du is a statistical parameter that results in a probability of slip of 5% at the service load level when the joint is designed using factored loads. = 0.85 for oversize and short slots parallel = 0.70 for long slotted holes D u = 1.13, ratio of installed bolt The resistance factor reflects the consequence of exceeding the “slip limit state.” As the consequence of slip gets more severe, the resistance factor is decreased. tension to specified minimum bolt tension μ = 0.30 clean mill scale, hot − dipped galvanized and roughened, etc. (Class A surfaces) μ = 0.50 unpa int ed and blast − cleaned, etc. (Class B surfaces) 47 There's always a solution in steel. 48 12 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Bolts in Tension • Bolts in Tension – some comments Capacity of a bolt in tension: product of the ultimate tensile strength of the bolt and the tensile stress area of the bolt (i.e. Fu Ast ) • Specifications directly reflect this calculated capacity (… (…to come) • Force in bolt must reflect any prying action effect • Preference: avoid joints that put bolts into tension, especially if fatigue is an issue • Use A325 bolts rather than A490 bolts • Minimize the prying action 49 50 Bolt tension + external tension Question… 1. Pretension the bolt → tension in the bolt, compression in the plates • pretensioned bolt in a connection 2. Add external tension force on connection → • apply external tension force to the connection • Bolt tension increases • do the bolt pretension and the • Compression between plates decreases external tension add? Examine equilibrium and compatibility… compatibility… 51 There's always a solution in steel. 52 13 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction And the result is… AISC rule, bolts in tension— • The bolt force does increase, but not by very much (≅ 7%) • This increase is accommodated φ R n = φ Fnt A b bolt area for nominal diameter nominal tensile strength within the design rule. φ R n = design tensile strength 53 What is nominal tensile strength, Fnt ? Adjusted area Call this Fnt 55 There's always a solution in steel. where Fnt = 0.75 Fu as tabulated in the Specification As we now know, the 0.75 really has nothing to do with Fu { Pult = 0.75 Fu A b So, the AISC rule for bolts in tension… φ R n = φ Fn t A b Pult = Fu A st = Fu (0.75A b ) or, 54 56 14 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Returning to shear splice joints, we still have to deal with the bearing capacity of the connected material. Bearing capacity (of connected material) d ShearShear-out of a block of material or yielding t P/2 P P/2 57 Bearing stresses at bolt holes… s Le 58 Shear-out rule… Shear - out is 2 ( τ ult × Lc × t ) Lc t1 t2 Needed: 1. shearshear-out rule 2. yield rule (deformation) or, R n = 2 ( 0.75 σu × Lc × t ) and AISC rule is: R n = 1.5 Fu Lc t d 59 There's always a solution in steel. 60 15 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Plate bearing… from tests: σb σ pl u = Plate bearing… Le d Making the substitution and using Fu ≡ σ pl u L ..after some arithmetic R n = σ b d t = σ upl e d t d R n = 3 d t Fu valid for L e ≥ 3 d 61 Further note re bearing… Finally, the AISC rule for plate bearing capacity is … When deformation a consideration, use R n = 1.5 Fu Lc t ≤ 3.0 d t Fu R n = 1.2 Fu L c t ≤ 2.4 d t Fu (with a φ-value still to be inserted) Why this difference, and when do we use the latter? (value of φ still to be applied) 63 There's always a solution in steel. 62 64 16 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Failure (ult. load) is by tensile fracture at location shown, regardless of geometric proportions. Block shear rupture Shear yield along vertical planes. Failure is controlled by ductility – not strength. 65 Basics… An example of shear + tension failure in a coped beam… Tr + Vr = φ A nt Fu + 0 .60 φ A gv Fy where A nt = net area in tension and 66 A gv = gross area in shear tension fracture shear yield …and some other requirements, including specific case of coped beams, limit on shear 67 There's always a solution in steel. 68 17 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Back to installation… Bearing-Type Connections— Installation of Bolts • Bolts can be installed to “snugsnug-tight condition — ordinary effort of worker using a spud wrench. (Pretension unknown, but usually small) 69 70 1. Calibrated Wrench Installation Installation — • Reliable relationship between torque and resultant bolt tension? NO ! (and forbidden by RCSC) • Establish relationship by calibration of the installing wrench. – bring parts together, continue turning nut, bolt elongates, tension develops in bolt, and clamped parts compress 71 There's always a solution in steel. 72 18 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Calibrated wrench, cont’d Hydraulic calibrator – • Adjust wrench to stall or cut out at • • • • desired level of bolt pretension Target value of pretension (RCSC) is 1.05 times specified min. value Calibrate using at least three bolts Calibration is unique to bolt lot, length, diameter, grade of bolt Washers must be used 73 2. Turn-of-Nut Installation 74 Does this definition of snug-tight seem a little vague? • Run nut down, bring parts into close contact • Work from stiffer regions to edges • Establish “snugsnug-tight” tight” condition (first impact of impact wrench or full effort of worker using a spud wrench) • Apply additional oneone-half turn (or other value, depending on bolt length) How influential is “snug-tight?” 75 There's always a solution in steel. 76 19 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction 60 Bolt Tension by Turning the Nut bolt tension 40 (kips) 60 Bolt Tension by Turning the Nut bolt tension 40 (kips) specified minimum tension 20 specified minimum tension 20 0.02 0.04 0.06 0.02 0.08 0.04 bolt elongation (in.) bolt elongation (in.) range of bolt elongations at snug bolt elongation at one-half turn bolt elongation at one-half turn 77 Inspection of Installation 78 Inspection of Installation • Principles: • Is bolt tension required? — if not, why – Determination of the bolt pretension after installation is not practical inspect for it ! • Know what calibration process is required – Understand the requirements e.g., are pretensioned bolts required? and monitor it on the job site • Observe the work in progress on a regular – Monitor the installation on the site basis – Proper storage of bolts is required 79 There's always a solution in steel. 80 20 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Inspection of installation: Snug tight only req’d…. Consider the following AISC cases — • Bearing-type connections 1. Bolts need be snugsnug-tight only 2. Bolts are pretensioned (but not a slipslipcritical joint) • Bolts in tension (A325 only) – only when no fatigue or vibration (bolt could loosen) 3. SlipSlip-critical joint 81 82 Inspection: if pretensioned bolts required… required… Inspection – snug tight • Bolts, nuts, and washers (if any) must meet the requirements of the specifications • All of requirements for snugsnug-tight case • Observe the prepre-installation verification process • Hole types (e.g., slotted, oversize) must – turn of nut, or; • Contact surfaces are reasonably clean • Parts are in close contact after bolts – other (direct tension washers, tensiontension-control bolts) meet specified requirements – calibrated wrench, or; • Calibration process done minimum once per day snugged • All material within bolt grip must be steel • Calibration process done any time conditions change 83 There's always a solution in steel. 84 21 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction An inspected joint (turn-of-nut) Inspection: for slip-critical joints • All of the above, plus • Condition of faying surfaces, holes, etc. • In addition to observing the calibration process, the inspection must ensure that the same process is applied to the field joints 85 86 87 88 and some other comments… • Pretension values greater than those specified are not cause for rejection. • Rotation tests are useful for short-grip bolts or coated fasteners (requirement is in ASTM A325 spec. and is for galvanized bolts) There's always a solution in steel. 22 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Actual pretensions, cont’d Actual pretensions, cont’d • For A325 bolts, turn-of-nut: – Average tensile strength exceeds spec. min. tensile by about 1.18 • A325, ½ turn-of-nut: 35% increase • A490, ½ turn-of-nut: 26% increase • A325 and A490, calibrated wrench: 13% increase etc. for other cases – Average pretension force is 80% of actual tensile • – Result is that actual bolt tension is about 35% greater than specified bolt tension Note: these increased pretensions are embodied in the specification rules 89 Some other options for bolts — 90 Tension Control Bolts region of constant torque ASTM F1852, F2280 groove at which shear will take place 91 There's always a solution in steel. 92 23 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Tension-Control Bolts Tension control bolts…. • NOTE: evidence that tips have • Advantages sheared off is not in itself evidence that desired pretension is present – Installation is from one side – Electric wrench is used – Installation is quiet • Consider limits: – Friction conditions are very high… high… • Disadvantages – Friction conditions are very low… low… – More expensive – Pre-installation calibration required • Hence, calibration is essential! 93 94 Direct Tension Indicators Direct tension indicators— • Protrusions formed in special washer • Protrusions compress as force in bolt is developed • Use feeler gage to measure gap (or refusal) • User must verify the process (like calibrated wrench) 95 There's always a solution in steel. ASTM 959 96 24 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Reliability of these... • • • • Some additional topics … Calibration required • Details, other topics Reliability same as calibrated wrench – washers (but not today!) TensionTension-control bolt is torquetorque-dependent – slotted or oversize holes (but not today!) LoadLoad-indicating washer is elongationelongationdependent – seismic design 97 Seismic design of connections 98 Pre-qualified bolted connections • Analyze structure in order to compute the forces – Use FEMA 350 and/or AISC Seismic Design Spec. • With forces now known, design connectors • Advisable to use pre-qualified configurations Note: some details not shown, e.g., continuity plates 99 There's always a solution in steel. 100 25 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction …bolted joints, seismic design • All bolts pretensioned • Faying surfaces as per slip-critical • Use bearing values for bolts AllAll-bolted connection – moderate quakes: no slip – major quakes: slip will occur and bolts go into bearing • Normal holes or short slotted only (perpendicular) • No bolts + welds in same faying surface 101 Seismic design, cont’d 102 It all started with rivets…. • Non-ductile limit state in either member or connection must not govern. • Calculate bolt shear strength as per bearing type but use 2.4 d t Fu bearing rule • Must use expected yield and ultimate strengths, not the specified values e.g. A36 plate : use 1.3 σ y spec. 103 There's always a solution in steel. 104 26 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Determine ultimate load for this gusset plate (which is one that was tested) Design example: gusset plate connection 14.76 2 30° Fy = 39.9 ksi Fu = 69.0 ksi 15.75 3@2.76=8.27 7/8 A325 bolts (holes 15/16 in.) 2.68 t = 0.26 in. 7.22 Pu test =164 kips (compression) 19.69 105 106 Set out the issues… Continuing… • Brace force in tension– • Brace force in compression – slip load of bolts (no slip at service load) – slip capacity of bolts (already checked for load in tension) – shear load of bolts – shear capacity of bolts (already checked for load in tension) – bearing capacity of plate – bearing capacity of plate (already checked) – block shear – block shear (doesn’ (doesn’t apply) – capacity of gusset plate in compression (New) 107 There's always a solution in steel. 108 27 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Slip load (calculate at factored load level) R n = μ D u h f Tb n s (per bolt ) μ = 0.30 (clean mill scale) h f = 1.0 (no fills)) Slip load calculation cont’d. R n = μ D u h f Tb N s (per bolt ) = 0.30 × 1.13 × 1.0 × 37.88 kip × 2 slip planes (std.holes) : = 25.68 kips / bolt A b = π d 2 / 4 = 0.60 in.2 (7/8 in.dia.) Fu = 120 ksi (A325 bolts) n s = 2 slip planes or, for 8 bolts, (φ = 1.0); R n = 205 kips Tb = spec. min. bolt pretension = (0.75 × A b )(Fu )70% = 0.75 × 0.60 in.2 ×120 ksi × 70% = 37.88 kips 109 Shear resistance of bolts 110 Bearing resistance (use φ = 1.0) φ R n = φ Fv A b R n = 1.5 Fu L c t ≤ 3.0 d t Fu Use ø =1.0 so that we can compare this load with the test load, assume threads in shear plane, no joint length effect 3 d t Fu = Fv = 90% [0.62 × 120 ksi] = 68 ksi 3 × 7 / 8 in. × 0.26 in. × 69.0 ksi = 47.1 k/bolt φ R n = 1.0 × 68 ksi × 0.60 in.2 = 41.0 kips (per bolt ) 1.5 Lc t Fu = or, for 8 bolts, 2 shear planes, threads in shear plane = (41.0 × 8 × 2)kips × 0.80 = 525 kips 1.5 × 1.53 in. × 0.26 in. × 69.0 ksi = 41.2 k 111 There's always a solution in steel. 112 28 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Block shear Bearing resistance… 2.00 …the governing value is 41.2 kips/bolt and, for 8 bolts— 3@2.76=8.27 Bearing resistance is 330 kips 2.68 A nt = (0.26)( 2.68 − 15 / 16) = 0.45 in.2 A gv = (8.27 + 2.00)2 × 0.26 = 5.34 in.2 Tr + Vr = φ A nt Fu + 0.60 φ A gv Fy 113 114 Brace force in compression: Block shear, cont’d Tr = 0.45 in.2 × 69.0 ksi = 31.0 kips Vr = 0.60 × 5.34 in.2 × 39.9 ksi = 127.8 kips and the total block shear resistance (unfactored) is (31 +128) =159 kips issue is sway buckling in this region 115 There's always a solution in steel. 116 29 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Whitmore method…. Checking the buckling… 30° • Use beam formulae to • Whitmore method (checks yield) • Thornton method (checks buckling) • Modified Thornton method (checks • buckling) • check perceived critical sections Use 30o , as shown to check yielding at location shown. Does not predict ultimate capacity very well, usually conservative but sometimes nonnonconservative 117 118 Thornton method, modified Thornton method… • Use longest (or average) of L1, L2, L3 to compute a buckling load on a unit width column, then apply this to the total width. • Use k = 0.65 in the column formulae As per Thornton method but spread load out at 45o 30° L1 45o L2 L2 L3 L3 119 There's always a solution in steel. L1 120 30 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Calculations for buckling capacity: Yam & Cheng gusset plate tests (U of A, 13 tests) Pu PW Pu PT Pu PT ' mean 1.33 1.67 1.06 std. dev. 0.26 0.12 0.08 Using scale dwg. L2 = 9.65 in. L1 Width of the 45o base is 19.2 in. L2 L3 φc Pn = φc A g Fcr (use φc = 1.0) we’ll use this method Fcr = (0.658 Fy / Fe ) Fy use k = 0.65 121 Consider a 1 in. wide strip that is 9.65 in. long length =9.65 And applying this to the total width… Pu = (6.91 k/in.) (19.2 in.) = 132 kips width = 1 and the test ultimate load on this particular specimen was 164 kips t = 0.26 r= I = A 1 × 1 × 0.263 12 = 0.0751 in. 0.26 × 1 and then completing the calculations, Pn = 6.91 kips (on a 1 in. wide strip) 123 There's always a solution in steel. 122 so, Pu / PT’ = 1.23 (The corresponding ratios for Whitmore and Thornton for this specimen were 1.31 and 1.80) 124 31 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction Some references — Summary of our calculations Brace Force Tension Compress. slip bolt plate block buckling test load shear bearing shear load 205 — 525 — 330 — 159 — — 132 — 164 Load and Resistance Factor Design Specification for Structural Joints Using ASTM A325 or A490 Bolts, Research Council on Structural Connections, 2004 (RCSC) (free download available at boltcouncil.org) boltcouncil.org) 125 126 References, cont’d. • G.L. Kulak, J.W. Fisher, and J.A.H. Struik, Struik, Guide to Design Criteria for Bolted and Riveted Joints, Joints, Second Edition, John Wiley, New York, 1987 (free download at RCSC website) • Bickford, John H., "An Introduction to the Design and Behavior of Bolted Joints," Second Edition, Marcel Dekker Inc., New York, 1990 Thank You! • G.L. Kulak, A Bolting Primer for Structural Engineers, Engineers, AISC Design Guide 17, Chicago, 2002 • Larry Kloiber and Larry Muir, “The 2010 AISC Specification: Changes in Design of Connections,” Connections,” Modern Steel Construction, Sept. 2010 127 There's always a solution in steel. Please give us your feedback! www.aisc.org/cesurvey 128 32 High Strength Bolts - Geoff Kulak April 14, 2011 American Institute of Steel Construction AISC Seminars AISC Seminars 2011 Spring Schedule – 6 seminar topics coming to 26 cities Upcoming Cities for April: Detroit – Houston – Denver Upcoming Cities for May: St. Louis – Boston - Miami Philadelphia – Sacramento 2nd Thursday of the month • No webinar in May • June 9, 2011: Extended Shear Plate Connections – • Larry Muir July 14, 2011: Design For Stability – Lou Geschwindner www.aisc.org/seminars www.aisc.org/webinars AISC eLearning AISC SteelCamp Over 60 hours of presentations available anytime, online. 2 day, 4 topics, 15 hours of Continuing Education, One low price. CEUs/PDHs are available. New York City – June 16-17 San Francisco – July 21-22 www.aisc.org/elearning www.aisc.org/steelcamp There's always a solution in steel. 33