SEISMIC DAMAGE ASSESSMENT OF HIGH-RISE RC STRUCTURES BASED ON MATERIAL DAMAGE MODEL

A plastic-damage constitutive model for concrete complying with the laws of thermodynamics is proposed based on continuum damage mechanics theory. The expression of plastic Helmholtz free energy that contains the plasticity and damage is used to describe the plasticity and damage degradation behavior of concrete. Moreover. the Weibull distribution hypothesis of damage index and damage energy release rate is introduced in the damage evolution equations, with the effects of damage considered in elastic stiffness. The damage constitutive equations, damage evolution equations and plastic deformation of concrete are derived. The results of the proposed model agree well with the experimental data. An effective three dimensional fiber beam-column element model is developed, for the seismic damage analysis of a high-rise structure on explicit dynamic numerical platform, with the uniaxial damage constitutive relations of concrete proposed in present paper being used, and the structure analysis results are compared to the data from shaking table test. The present work shows that the seismic damage assessment based on the proposed model and strategy is reasonable and reliable in the seismic performance analysis of high-rise RC structures.