Digital Simulation of Welding Process to Optimize Residual Stresses and Microstructure of Welded Suspension Component 2022-28-0380

Automotive suspension system forms the basis for the design of vehicle with durability, reliability and NVH requirements. The automotive suspension systems are exposed to dynamic and static loads which in turn demands the highest integrity and performance against fatigue based metallic degradation. The growing demand for light-weighting has culminated into numerous designs of rear twist beam suspension systems. However these designs drive their design flexibility by incorporating multiple welding joints into the suspension system. Welding joints helps in designing complex automotive systems. However, these welding joints bring in weak points as welding process itself degrades parent material and introduces areas with high tensile residual stresses. These areas with tensile residual stresses are susceptible to undergo fatigue failure. Thus, there is a need to improve welding process to mitigate harmful tensile residual stresses. The present paper describes a weld process digital simulation approach for minimizing welding induced tensile residual stresses. The present work includes digital simulation of weld sequencing and welding parameters to predict and optimize tensile residual stresses. The design approaches for weld joint type, weld sequencing and welding parameters were obtained by simulating welding process on commercially available software. The output from welding simulation were physically verified by conducting X-ray Diffraction residual stress analysis on physical welded assembly. The metallurgical features such as microstructure and weld hardness were also predicted and correlated with physical observations. The study concluded into the development of an approach to digitally predict and optimize weld process parameters for obtaining optimum residual stresses and microstructural features.