Research On The Collapse Mechanism Of Spatial Trusses

The dynamic characteristic of the spatial truss is different from multi-layer or high-rise structures. Thorough research on the collapse mechanism under dynamic loads for ensuring its security is of great theory sense and very important practical engineering value.On the basis of numerical analysis, this paper studies the collapse rule of spatial trusses under the action of dynamic loads, which includes: taking orthogonal square pyramid spatial grids as example, this paper set up the finite element modal of spatial grid structure by the finite element analysis software ANSYS, and analyzed its natural vibration characteristic and linear harmonic response; the collapse process of spatial trusses respectively under static load and simple harmonic load are analyzed; according to the dynamic characteristic of the spatial truss, two basic breakage modal (dynamic strength breakage and dynamic stabilization breakage) are analyzed; all the data of the two breakage modal has been analyzed.It is found that the collapse of spatial trusses is mainly dynamic strength breakage. The critical load of dynamic damage is determined mainly by the displacement, and secondly by the extent of plasticity of the whole structure; the dynamic breakage criterion of the spatial truss under simple harmonic load is put forward; under the effect of earthquake, the breakage of structure is the combination of dynamic strength breakage and dynamic stability breakage; under the effect of static load, the structure can has larger plastic yield, and the breakage is the mutual result of both plastic and deformation.