Numerical study of equal-channel angular pressing based on the element-free Galerkin method

Abstract

AbstractBased on the flow formulation for rigid–plastic/viscoplastic materials, a rigid–plastic/viscoplastic element-free Galerkin method is established to realize the simulation of massive metal-forming processes. Stiffness equations and solution formulae are derived in terms of the incomplete generalized variational principle. The transformation method is employed to exert the essential boundary condition in the local coordinate system. The arctangent frictional model is used to implement the frictional boundary conditions, and the transform matrix from the global coordinate system to local coordinate system is given. Being similar to finite-element simulations, the key techniques for metal-forming meshless analysis such as the treatment of the rigid region, dynamic adjustment of the boundary nodes, and treatment of volumetric locking are developed. The analysis software is developed. The equal-channel angular pressing process is simulated numerically using the software. The effective strains become larger and more uniform with increasing curve angle Ψ. On the other hand, the forming load increases greatly with the increase in the curve angle Ψ. The effective strains change slightly with the change of the frictional status between the die and the workpiece. However, the frictional status influences greatly the forming load.