混凝土MAZARS模型的非局部化及其数值实现与验证

Nonlocal Concrete MAZARS Model and its Numerical Implementation and Validation

MAZARS模型是在损伤力学框架内建立的经典混凝土本构模型之一,由于其属于局部本构模型,故基于MAZARS模型的混凝土损伤有限元分析存在单元尺寸依赖性,无法保证分析结果的客观性,此外,以非线性有限元分析能力著称的ABAQUS平台尚未内置MAZARS模型.为实现在ABAQUS平台上开展基于MAZARS模型的混凝土损伤破坏的客观分析,本文将MAZARS模型与积分形式的非局部理论相结合,给出了非局部MAZARS模型的理论表达,并提出了与ABAQUS数据传递方式相适应的的非局部MAZARS模型数值实现方法.在此基础上,利用ABAQUS提供的UMAT、UEXTERNALDB以及USDFLD 3个子程序接口,通过二次开发完成了非局部MAZARS模型在ABAQUS平台上的数值实现,拓展了ABAQUS在混凝土损伤方面的分析功能.算例分析验证了本文所提出方法的可行性与程序开发的正确性.

The MAZARS model is one of the classical constitutive models of concrete proposed in the framework of damage mechanics.However,the damage finite element analysis of concrete based on the MAZARS model has shown the dependence on the element size due to the fact that the MAZARS model is local.In addition,the MAZARS model is not available in the widely used FEM platform ABAQUS.In order to realize the objective analysis of concrete damage by taking use of ABAQUS,the theoretical formulations of the nonlocal MAZARS model was presented,followed by its numerical implementation strategy suitable for the data transmission method of ABAQUS.Based on the above mentioned,the numerical implementation of the nonlocal MAZARS model in the platform of ABAQUS was accomplished through the secondary development using the subroutine UMAT,UEXTERNALDB and USDFLD,which can expand the function of ABAQUS concerning concrete damage analysis.The feasibility of the proposed strategy and the correctness of the developed program were verified through numerical examples.