EFFECTS OF MEMBER BUCKLING AND YIELDING ON ULTIMATE STRENGTHS OF SPACE-TRUSSES

Space trusses represent one type of structure whose ultimate loading c apacity cannot be solely determined from linear analysis. In compariso n with the large amount of research on the geometric nonlinear behavio urs of space trusses, relatively little work has been conducted on the effects of member buckling and yielding. In this study, constitutive laws that consider these effects are first derived for a hinged bar. S uch constitutive laws are then included in an incremental-iterative pr ocedure for tracing the postbuckling responses of space trusses, based on a rigorous, updated, Lagrangian formulation. From the numerical st udies, it is concluded that the buckling of individual members can res ult in drastic reduction of the ultimate loading capacity of space tru sses. The effect of member yielding, however, tends to affect the dura tion of the elastic range in the postcritical stage for most structura l steels. Copyright (C) 1996 Elsevier Science Ltd.