Residual Stress Modeling Strategies for Mitigation and Stress-Relieving Processes

Abstract This article centers on processes used to reduce residual stresses in manufactured components and structures, including thermal relaxation, microplastic relaxation, and microplastic relaxation under cyclic conditions. These processes fit into two primary means to relieve residual stresses: thermal processing to enable local plasticity and creep mechanisms, and mechanical processing to enable local or global yielding. Computational modeling can be used with each of these mechanisms to assess how effective they are at reducing residual stresses. It describes a progression of different creep models and solution procedures, from a simple analytic model with a closed-form solution to a complex displacement-based finite-element numerical solution that is capable of incorporating both material and geometric nonlinearities. The article discusses the implementation of creep data and models for stress-relief simulation. It describes more advanced techniques, beyond the simplified approaches for approximate solutions, that are applicable to transient creep, advanced constitutive models, and complicated stress and temperature loading histories. An example highlights the difference between a steady-state and transient creep analysis solution using a spinning disk that creeps at elevated temperature. The article also presents an overview of mechanical stress-relief modeling.