Shear Connectors

[bcy]

Chapter I Design of Composite Member of AISC 360 gives formulas to calculate the nominal strength of shear connectors, either shear studs or channels. The example from the CD accompanied with the AISC manual designs shear connectors at nominal strength level. If the horizontal shear between the max and zero moment is calculated based on the LRFD or ASD factored loads, what is the value of phi (LRFD) or Omega (ASD) I should use to determine the number of shear connectors? Thanks.

 

[Ryan O.]

Phi and Omega factors are not required when calculating the required number of shear studs. You are just trying to provide enough shear studs to develop the lesser of the concrete crushing strength of the slab or the tensile yielding strength of the steel section. Both of these conditions are independent of whether LRFD or ASD is used. The equations for concrete crushing and tensile steel yielding can be found on page 16.1-85 in the 2005 steel manual (eqn. I3-1a and eqn. I3-1b). The SERM has a pretty decent section on composite beam design and explains it a little more clearly. Hope this helps.