侧向挤压过程的耦合无网格-有限元法数值模拟

应用刚塑性耦合无网格-有限元法,对平面侧向挤压过程进行数值模拟.采用修正的罚函数法约束体积不可压缩条件,避免体积闭锁现象.采用边界奇异核方法,直接、准确地施加本质边界条件.针对侧向挤压工艺的特点,将无网格节点布置在变形剧烈的区域,充分发挥其处理大变形问题的能力;在变形较小的区域采用有限元单元,利用其较高的计算效率.数值模拟结果表明,该耦合方法对于侧向挤压这类局部成形问题的求解具有良好的效果.

Numerical Simulation of Lateral Extrusion by an EFG-FE Coupling Method

A rigid-plastic element-free Galerkin-finite element(EFG-FE) coupling method was developed for the numerical simulation of plane lateral extrusion process.Modified penalty method was used to treat incompressible constraints to avoid volumetric locking.Boundary singular kernel method was adopted to impose essential boundary conditions directly.For lateral extrusion process,the severely deformed region is discretized to EFG region,for its ability to deal with large deformation.While minor deformed region is modeled by FE elements,for its higher computational efficiency.The results of simulation prove that the coupling method is accurate and valid for local deformation processes such as lateral extrusion.