Dynamic Properties Analysis Of The Single-layer Spherical Latticed Shells Under Earthquake Excitation Considering Damage Accumulation Effect

The material damage is not considered in the most existing seismic researches of single-layer lattice shells structure, and the theoretical methods in service is not reliable enough. In this thesis, a damage criterion is defined in the material model, and the dynamic response of the single-layer lattice shells structure under seismic action is studied. The main contents and conclusions include the following parts.First, an introduction of current research status and the main existing achievements in the research field of lattice shells structure is presented. Moreover, the research methods for studying the dynamic properties of the components in steel structure are introduced.Second, the mixed hardening model considering damage accumulation effect is proposed based on the theory of elastic-plastic FEM. The theory of constitutive model is compiled as the subroutines of ABAQUS. The accuracy, reliability and practicality of the proposed constitutive model are verified by the comparison between results of numerical analysis and experiment.Third, the effects of member buckling and the damage accumulation are analyzed respectively in the calculation of ultimate capacity. The numerical results reflect that the consideration of the effect of damage accumulation would significantly reduce the ultimate bearing capacity, and the ultimate capacity without the consideration of buckling effect is severely overestimated.Finally, considering buckling of the member, fifteen single-layer shells lattice structures with different spans, rise-span ratios and loading conditions are modeled, and the effect of cumulative damage on the dynamic response under seismic action is quantitatively demonstrated in this thesis.