الفهرس | Only 14 pages are availabe for public view |
Abstract The improvement of nonlinear behavior of space trusses is a major aim for the recent researchers. The investigators summarized the mode of failure of space trusses in two modes. The first mode was due to the brittle failure of the top compression members while the failure due to yield of the tension members was the second mode. Composite technique is one of the methods used to improve the brittle failure of space trusses. This technique depends on the covering slab of the space trusses that works with the top members of space truss in composite action. This thesis focuses on the improvement of nonlinear behavior of space trusses using top sandwich panel slab. This panel works with the top members of space trusses in composite action. Top sandwich panel slab is considered one of the common types which used to cover the steel structure which characterized by insulation of thermal and light weight. Three different models of sandwich panels were studied experimentally and theoretically under central load to study their flexure behavior up to failure. Also two finite element models are employed for analysis of space trusses (noncomposite and composite) using ANSYS v12 program were studied. The two models were verified by studying four previous published space trusses by the two models and the results indicated that the two models can predict the general collapse behavior of the space trusses. Also three composite trusses with top sandwich panels were analyzed theoretically by ANSYS program. The results from the composite space trusses were compared with the results of non-composite trusses. These comparisons indicated that using the composite action between the top sandwich panel slab and the top member of space trusses increases the ductility of trusses, decreases its brittle failure and increases the truss capacity. |