混凝土准脆性界面裂纹本构模型比较

Comparison of constitutive models of interface cracks for quasi-brittle materials

以混凝土界面断裂分析为目的,选取若干典型的层间界面准脆性断裂的本构模型进行分析和数值模拟对比研究。在局部本构水平上,采用这些界面裂纹本构模型,对各种载荷工况下材料的准脆性断裂行为进行数值模拟。在对选择的典型黏性界面裂纹进行定性分析比较时着重考虑以下两点:①采用选择的模型对I型裂纹和II型裂纹的断裂行为进行数值计算;②对混合型断裂载荷作用下模型的扩容行为特性进行数值分析。通过对数值结果的分析比较得出结论:库仑型裂纹模型比较适合模拟复杂载荷下的界面断裂行为,但是其扩容特性仍有待改善。

Concerning on the-modeling of the quasi-brittle fracture process at interface cracks of quasi-brittle materials, a comparative snalysis was performed based on some typical constitutive models of interface cracks. Numerical simulation of the cluasi-britle fracture behaviors with the selected models was camied out at local constitutive level,Aiming at the simulation of quasi-brittle fracture of concrete-like materials, the qualitative comparison of the selected models was focused on the follow aspect, i.e.the simulation of the fractttre behaviors of crack mode I and crack mode II by use the selected raodels and the simulation d dilataney properties of the selected models under mixed-mode fracture loading conditiorts.It is concluded that the Coulomb-type crack model is suitsble for simulation d the interfacial fracture under mixed-mode fracture loads, however further work is still needed for improvement of its dilatancy properties.