AISC LRFD 1.pdf

66 BOLTS AND THREADED PARTS [Sect. J3.connections designed on the basis of standard holes without reducing the designshear stress of the fastener to that specified for slotted holes.8b. Slip-Critical Connections Designed at Service LoadsSee Appendix J3.8b.9. Combined Tension and Shear in Slip-Critical ConnectionsThe design of slip-critical connections subject to tensile forces shall be in accordancewith either Sections J3.9a and J3.8a or Sections J3.9b and J3.8b.9a. Slip-Critical Connections Designed at Factored LoadsWhen a slip-critical connection is subjected to an applied tension T u that reduces thenet clamping force, the slip resistance r str according to Section J3.8a, shall be multipliedby the following factor:u1 - (1.13 TNb b )whereT b = minimum bolt pre-tension from Table J3.1or J3.1M, kips (kN)N b = number of bolts carrying factored-load tension T u9b. Slip-Critical Connections Designed at Service LoadsSee Appendix J3.9b.10. Bearing Strength at Bolt HolesBearing strength shall be checked for both bearing-type and slip-critical connections.The use of oversized holes and short- and long-slotted holes parallel to theline of force is restricted to slip-critical connections per Section J3.2.The design bearing strength at bolt holes is R n ,where = 0.75and R n is determined as follows:(a) For a bolt in a connection with standard, oversized, and short-slotted holes independentof the direction of loading, or a long-slotted hole with the slot parallelto the direction of the bearing force:when deformation at the bolt hole at service load is a design consideration:R n =1.2L c tF u 2.4dtF u(J3-2a)when deformation at the bolt hole at service load is not a design consideration:R n = 1.5L c tF u 3.0dtF u(J3-2b)(b) For a bolt in a connection with long-slotted holes with the slot perpendicular tothe direction of force:R n =1.0L c tF u 2.0dtF u(J3-2c)LRFD Specification for Structural Steel Buildings, December 27, 1999AMERICAN INSTITUTE OF STEEL CONSTRUCTIONT