自适应无网格热弹塑性接触模型研究

提出一种自适应无网格热弹塑性接触求解模型,求解接触问题的线性规划-增量初应力法与基于应变能梯度的自适应无网格法相结合,给出了模型计算理论和算法实现.通过圆柱体与弹塑性平面热弹塑性接触算例对模型进行验证.对是否考虑材料应变硬化,是否考虑摩擦力和热输入,是否考虑材料屈服强度温度相关等情况的两种算例进行了讨论.结果表明,该模型能有效地求解考虑不同情况下的热弹塑性接触问题,在较真实地模拟接触状况的同时,具有较高的计算精度和计算效率.

Research on an adaptive meshless thermo-elasto-plastic contact model

An adaptive meshless model is proposed to solve two-dimensional thermo-elasto-plastic contact problems. The strain energy gradient-based error estimation and the local adaptive refinement strategy for the adaptive meshless element-free Galerkin-finite element (EFG-FE) coupling method are combined with linear programming technique-initial stiffness method for contact problem. The model's principle explanation, arithmetic analysis and numerical implementation are given. The example of rigid cylinder contacting with an elasto-plastic plane is analyzed to validate the adaptive meshless model. The thermal effects on the contact pressure, stresses distributions with different input parameters under the thermo-elasto-plastic contact conditions are discussed. The examples, which have considered the different conditions such as strain-hardening property of the materials, the frictional force and the frictional heat inputs and temperature-dependent yield strength, are also computed. According the two examples, the results of the contact pressures and the stresses distributions obtained from the last refinement stage nearly approach those from the uniformly refined solutions, while the cost of the CPU time for the adaptive refinement model is only about 7%-10% of that for the uniform refinement model. The results indicate that the adaptive refinement model is accuracy and efficient.