Analysis Of Elastic-plastic Performance Of Two-way Suspended Lattice Cylindrical Reticulated Shell Under Prestress Force Of Different Magnitudes In Strong Earthquake

With the vigorous development of social economy and the continuous progress of science and technology,there is an increasing demand of human society for the space structure buildings.Currently,people's requirement for space structure is not limited to satisfying the large-span use condition.Reasonable economic indicators,elegant art forms as well as the requirements of sustainable development,etc.,have become the evaluation indexes for space structure.As a form of space structure,the suspended-dome structure which provides a perfect rigid-flexible combination can well satisfy the above performance indexes and has been applied widely.In China,frequent earthquake disasters have been threatening the safety of people's lives and property,therefore,the structural seismic design is particularly important.For the suspended structure,the prestress action as a key factor of structural stress has great influence on the structural internal force distribution and also can directly affect the seismic response of the entire suspended structure.Therefore,it is essential to study the influence of prestress force of different magnitudes on the structural seismic performance during an earthquake.In this paper,with the two-way suspended structure as the study object and by use of SAP2000 software,40% and 30% prestress force are applied to the structure respectively to perform the elastic-plastic time-history analysis for the two structures under strong seismic action and to make a comparison of the dynamic responses,structural deformation,failure modes and stress states of cable of the two structures.The conclusions are as follows:1.Under the action of the three kinds of combined wave,with 40% and 30% prestress force applied to the suspended cable of the two-way suspended lattice shell,horizontal stiffness is stronger than the vertical stiffness.2.Under the action of the three kinds of combined wave,the seismic bearing capacity of the two-way suspended structure applied with 40% prestress force is slightly less than that of the two-way suspended structure with 30% prestress force.3.Under the action of the seismic wave,the plastic performance of the two-way suspended lattice shell structure applied with 30% prestress force is better than that of the two-way suspended lattice shell structure with 40% prestress force.4.A string prestressed reticulated shell string pillar level is higher,the ductility performance will be worse.5.For both structures,the weak part of the seismic response is at the middle position of the upper shell of the structure,thus attention shall be paid to the design of bearing capacity of this part.6.With 40% and 30% prestress force applied to the suspended cable of the two-way suspended lattice shell and in the whole process of the seismic wave action,the suspended cable and the stable cable are not subject to yielding or relaxation failure and can always provide suitable prestress for the lattice shell,thus being of good working performance.7.Under the action of the seismic wave,the seismic performance of substructure of the two-way suspended lattice shell structure applied with 30% and 40% prestress force is stronger than that of the superstructure.