改进的复合材料细观模型周期性边界条件施加方法

Method and realization of applying periodic boundary conditions to microscale model of composite materials

为了解决降温法施加周期性边界条件过程中容易产生反向应变的问题,在细观模型中增加参考节点,提出了通过位移约束方程的方式来施加周期性边界条件,并利用矩阵的秩来消除过约束问题。通过数值算例与降温法进行对比,发现位移法能避免细观模型产生反向应变的现象。该方法对研究计算多尺度方法中细观模型的边界条件有一定意义。

In order to solve the problem of reverse strain in the process of applying periodic boundary conditions by thermal stress method,periodic boundary conditions are applied by adding reference nodes to the microscale model and displacement constraint equations are established. The rank of matrix is used to eliminate the problem of over-constraints. By comparing the numerical examples with the thermal stress method,it is found that the displacement method can avoid the phenomenon of reverse strain in the microscale model,which is expected to be extended to multiscale multi-field coupling problem.