Experimental Study of Behavior of Composite Space Trusses

Abstract

From previous studies on space trusses it has been found that a major problem facing such structures is the brittle type of failure, caused by the successive buckling of a series of critical compression‐chord members. The present study investigates the possibility of using either overstrengthened top chord members or a concrete slab acting compositely with the top chord to improve the behavior of space trusses. The concrete slab was expected to reduce the buckling problems of the top chord members, to increase the stiffness of the structure, and to induce a ductile type of failure by making the overall behavior dependent mainly on the tension characteristics of the bottom chord members. The present study has indicated that a composite concrete top chord is more effective than overstrengthened top chord members in reducing the likelihood of brittle failure modes developing in space trusses. An analytical study based on the finite‐element method was carried out using a computer program developed and verified by the writers.