Substrate-centric comparative analysis and validation of finite element and empirical models for residual stress prediction in remanufactured WAAM-fabricated SS316 parts

This study presents a comparative analysis of computational simulations, empirical and experimental validation for predicting residual stresses in SS316 components fabricated via Wire Arc Additive Manufacturing (WAAM). The focus is on the substrate’s role in influencing heat dissipation and stress distribution during remanufacturing. WAAM-produced SS316 parts are prone to significant residual stresses due to steep temperature gradients and rapid cooling rates, which are critical factors affecting their mechanical properties and fatigue life. To address this, Finite Element Analysis (FEA) was performed using Ansys Workbench 2022 R2 to simulate thermal behaviour and stress distribution. Temperature variations were assessed using Ansys and verified through a data acquisition system, while residual stresses in the substrate were evaluated through simulation, micro-indentation, and validated by the hole drilling method. The comparison between the FEA and empirical data, when experimentally calibrated, showed acceptable discrepancies, confirming the model’s accuracy in predicting thermal and residual stress distributions. Hole-drilling experiments on samples with a 180-second interlayer cooling period recorded stresses of 40.1 MPa, 43.9 MPa, 43.8 MPa, and 40.7 MPa across four points, while simulations estimated thermal stresses at 38.6 MPa, 40.9 MPa, 40.8 MPa, and 38.9 MPa, with percentage differences ranging from 3.63 to 6.91%. Empirical measurements recorded values of 39.6 MPa, 41.1 MPa, 41.6 MPa, and 39.8 MPa. Empirical measurements closely aligned, with deviations from simulation results between 1.95% and 2.99%. This integrated approach combines empirical and FEA-based assessments to accurately predict residual stresses, enhancing computational efficiency and structural integrity in remanufactured WAAM-fabricated SS316 components.