Elasto-Plastic Analysis Of Spatial Grid Structures Under Seismic Excitations Considering Damag Cumulation

The breakage of the building usually dued to the damage accumulation,Structural damage history doubtless will produce the important influence on buildingat follow-up enlistment with the resistance and remain life.However, the study aboutstructural resistance took no account of damage accumulation, that analysis certainlyaffected the accuracy of the analysis result. Earthquake is one of the main factors tocause damage accumulation, therefore, it have extensive actual and social meaning toanalyze structure considering damage accumulation under seismic excitations. In this paper, basing on damage mechanics, author studied the damage effect onspatial grid structures under seismic excitation, deduced damage variable undercircling loading, established the method for expressing reaction to spatial gridstructures under seismic excitation with single damage variable. Basing on therelationship between the forces and deformations in elasto-plastic phase, anhysteresis model of structure members considering damage cumulation wereestablished, and deduced the element elasto-plastic stiffness matrix and the wholeelasto-plastic stiffness matrix for spatial grid structures, got the modified finiteelement analysis model, and modified dynamic equilibrium differential equation.Finally, an example is given, analyzed a spatial grid structures under seismicexcitation and got some conclusion.