Meticulous Study On Dynamic Performance Of Suspend Dome Structure Under Severe Earthquake

The dynamic performance of suspend-dome structures under severe earthquake is an important issue. At present, in theory, there are still two problems. First, the steel constitutive models of the calculation model are too simple, resulting in the misjudgments of dynamic failure mechanism and failure characteristics, on the other hand is a simplistic calculation model enough to simulate the real structure.According to the first issue, a stress-damage constitutive model was introduced and the dynamic time-history responses for an 8 points supporting suspend-dome subject to different seismic acceleration excitations were investigated with bilinear constitutive model and stress-damage constitutive model respectively. The comparison of two kinds of material models was revealed the importance of taking stress-damage constitutive model. And some physical quantities of the suspend-dome structures by using stress-damage constitutive model, such as the maximal displacement, the number of plastic members, strain energy and kinetic energy density of members, stress and stress change rate were analyzed, and revealed the dynamic characteristics of the structure, such as failure criteria and failure characteristics.As regards the other issue, finite element analysis of welded ball joints bearing axial force and bending was finished to get the M-θhysteresis curve of welded ball joints considering the material damage cumulative modal, and semi-rigid joint modals were established. Furthermore, the inflection to the dynamic characteristics of semi-rigid joints, rigid zone of joints and material damage cumulative modal are studied under severe earthquake.Through the above study, the following conclusions were obtained: 1. The inflection of semi-rigid joints, rigid zone of joints and material damage cumulative modal should be considered during the dynamic time-history responses for suspend-dome structures under severe earthquakes. 2. semi-rigid joints and material damage cumulative modal can make the uniformity of structural stiffness, the redistribution of internal forces and the increase of structural ductility. 3. The considering of semi-rigid joints, rigid zone of joints and material damage cumulative modal could induce the change of dynamic failure mechanism and failure characteristics. 4. There are two weak parts in the suspend-dome, the center single-layer reticulated shell and the second node location close to the supports, due to the elastic support of the vertical bars, the stiflness of suspend-dome is not uniform.