Research On Dyamic Responses Of Combined System Of Spatial Steel Tube Arch Truss Subjected To Earthquake

With the appearance of new building material and development of construction technology, large scale structure was used widely. Especially the arch trusses were more and more applied in many structures, such as gymnasiums, departure halls, convention and exhibition centers etc for its light weight, big span and graceful sculpt. While compared with the application of arch truss, the research on its dynamic stability was still staying at the stage of beginning and there were few achievements at home or overseas. The dynamic responses of steel arch truss under earthquake impulse loads were mainly discussed in this paper.Based on considered the geometric and material dual-nonlinearity and Rayleigh damping (damping ratio is 0.02), the dynamic responses of 110m-spans steel tube arch truss approximate to real project under earthquake excitation were analyzed in detail by using the finite element software ANSYS. During this analysis, suitable element types were taken and a dual-linearity kinematic hardening mode was set up.1,The main tasks are as follow:(1) The whole dynamic responses process of arch truss mode was tracked under X-action of EL Centro seismic wave.(2) The differences of dynamic responses under EL Centro seismic wave inputted in different action were analyzed.(3) The differences of dynamic responses under three seismic waves(EL Centro seismic wave,Ninghe wave,artificial wave) inputted in tri-action were compared.(4) The differences of dynamic responses caused by the variety of dip angle of primary truss and equivalent mass of roof under EL Centro seismic wave inputted in tri-action were discussed.(5) The differences of dynamic responses considered damping or not under some seismic waves inputted in tri-action were studied.2,The main achievements are as follow.(1) When the seismic acceleration amplitude is smaller, the response of characteristics indexes linearly increase; with the increasing of the seismic acceleration amplitude, some members turn into plasticity and the equilibrium position of the whole structure comes into being transition; when the acceleration peak reached the critical load, the deformation in the middle members of primary truss is serious and the bucking of the whole structure was taken place.(2) Under the seismic wave inputted in different actions, the critical load of arch truss under X-action was the biggest, that under tri-action was the smallest, while that under Z-action was in the middle.(3) The order of critical load of arch truss under three seismic waves ranked by value of big to small was Ninghe wave,artificial wave,EL Centro seismic wave.(4) The smaller the equivalent mass of roof or the bigger the dip angle of primary truss, the better the structural power performance and the higher the critical load.(5) The critical load of arch truss was enhanced by the energy expenditure of damping.