Research On Nonlinear Damage Model Of Fully-graded Concrete

Nonlinear deformation and damage of concrete dam structures will occur under strong earthquakes.In order to realize the nonlinear numerical simulation of the whole process of the disaster damage evolution of the concrete high dam system under strong earthquakes,the nonlinear behavior of the concrete needs to be clarified in depth,the concrete damage evolution rule of the fully-graded dam should be studied,and the mechanical damage model of concrete damage should be established for more effectively reflecting of its nonlinearity,therefore,studying the nonlinear deformation characteristics of concrete and its damage parameters will undoubtedly have practical engineering application value.This studying is focused on investigating on the dynamic damage material tests of the fully-graded concrete and to establish the relationship between the stress and nonlinear deformation,and the evolution of the damage with nonlinear deformation of the fully-graded dam concrete in a complex stress environment.This article is based on Chinese IWHR "fully-graded Xiluodu arch dam concrete dynamic characteristics test and analysis of research data" experimental data,including four concrete samples in uniaxial tensile,pressure test and reciprocating load pull,pressure test data;The damage evolution of single,cyclic loading and axial compression test data is analyzed and summarized based on the damage plastic mechanics model.The specific work contents are mainly divided into the following aspects.One,based on the distribution of concrete specimen under uniaxial tensile compressive data including limit stress,ultimate strain,modulus of elasticity mechanics parameters,such as through the contrast analysis of the relationship between inductive levels 4 with concrete materials in single shaft,the stress and strain equation under cyclic loading state parameters.Two,through the analysis of the stiffness degradation and residual plastic strain data of the cyclic loading tensile test of all grade concrete specimens,the damage parameter evolution law of concrete materials is built.The damage relation is derived directly from plastic strain and total strain instead of incremental iterative calculation.Three,the damage evolution law to expand the cyclic loading test is applied to the complete stress strain curve of damage calculation,using simulation software simulation of concrete and compressive loading process of stress and strain and damage distribution,contrast analysis theory test were damaged.Through the above research,the nonlinear deformation and plastic damage of concrete are thoroughly understood.At the same time,the damage rule can be summarized for practical engineering application.