Study On Concrete Mesoscopic Statistical Damage Constitutive Model Under Uniaxial Compression

The structure of concrete structure is applied very widely in the world, itsmechanical properties and constitutive relations have been the research emphasis in theengineering. However concrete material is very complex and uncertain characteristics,so far there is not widely applicability constitutive model of concrete. Analysis ofdamage mechanism of concrete, this paper combined with the failure process ofconcrete, has carried on the theoretical exploration for concrete mesoscopic statisticaldamage constitutive model.In this paper, compared the basic theory of the mesoscopic damage mechanics andthe macroscopic continuum damage mechanics, it is pointed out that based on themesoscopic phenomenological statistical damage constitutive model is a concreteresearch new direction. According to synergetics and mutation in the nonlinear sciencetheory, the damage of concrete can be divided into uniform damage and local failurephase. It is thought that the critical state is constitutive model for the final breakdownpoint.In this paper, through the analysis of failure mechanism of concrete, according tothe principle of parallel bar model of elastic brittle and Weibull distribution probabilitydensity function of the distribution characteristics of similar to concrete strengthprobability distribution, concrete under uniaxial compression statistics of mesoscopicdamage model is established. Using two after freeze-thaw effect of concrete underuniaxial compression test, to determine constitutive model parameters, analysis oftheoretical results and experimental results to validate its rationalityFinite element analysis is an effective method for large structure design, butconcrete structure finite element analysis results have high precision, the chosen constitutive model can accurately describe the constitutive behavior of materials. usingABAQUS finite element analysis software, simulates concrete prism specimens underuniaxial compression mechanical properties.The analysis of large structure is a kind of effective tool, but the error of finiteelement analysis of concrete structures mainly depends on the selection of concreteconstitutive model can describe the constitutive behavior of materials well enough. Inthis paper, Comparing the constitutive model of the simulation results with test results andthe simulation results computed by the constitutive model recommended by The concretespecification. Indicates that the constitutive model is suitable for the software ofABAQUS and can accurately simulate the concrete constitutive behavior.