利用近场动力学方法(PD)在模拟不连续变形问题的独特优势和有限单元法(FEM)的计算效率,提出近场动力学与有限单元法混合建模的方法,并用于求解断裂力学问题.裂纹出现的区域采用改进的近场动力学微观弹脆性(PMB)模型进行离散,其他区域采用有限元离散,通过杆单元连接不同的子区域.在隐式求解体系下实现了两种方法的混合建模,该模型在求解静力学问题时无需引入阻尼项,有效提高了计算效率和计算精度.通过模拟计算简支梁的弹性变形和三点弯曲梁I型裂纹的扩展过程,与理论解吻合良好,验证了提出的混合模型和求解方法的准确性和有效性.
A hybrid model of peridynamics(PD)and finite element method(FEM)was proposed and applied to solve problems of fracture mechanics in order to combine the unique advantage of PD in solving discontinuities and the computational efficiency of FEM.The improved prototype microelastic brittle(PMB)model of peridynamics was utilized for the regions where material failure was expected.The region without failure was discretized by FEM.The truss element was introduced to bridge peridynamic subregions and finite element subregions.The hybrid model is based on the implicit schemes,and it need not consider a fictitious damping term in solving static problems.The computational efficiency and accuracy of the model were improved.The static elastic deformation of a simply supported beam and the propagation process of mode I fracture in a three points bend beam were simulated to verify the accuracy and utility of the presented model.Results obtained by the model agreed well with the theoretical solutions.