A numerical method to predict work-hardening caused by plastic deformation

The hardening layer might form on the machined workpiece surface especially under worn cutting edge, which is caused by plastic deformation. The increased surface hardness affects the using or re-processing performance of workpiece. The finite element method was adopted in most previous works to acquire the elastic-plastic behavior and hardening layer. However, the complexity of meshing is an obvious limitation. To address this, a meshless finite block method with infinite element is developed to conduct elastic-plastic deformation analysis and hardening layer prediction for the first time. The Lagrange interpolation constructs the differential matrices in normalized domain with Chebyshev's distribution of nodes. The infinite element was introduced by a block of quadratic types to reduce the nodes used. The Prandtl-Reuss incremental theory with isotropic hardening was applied. Good agreements on stress and strain predictions were observed between this method and finite element method (ABAQUS), while a higher convergence of this method was demonstrated. The stress and strain results of ABAQUS is more sensitive to node density, which might bring larger error. Finally, the simulated work-hardening layer results show that the traction force plays a more important role than pressure force to cause a larger plastic deformation and a deeper work-hardening layer.