Inherent Strain Method and Thermal Elastic-Plastic Analysis of Welding Deformation of a Thin-Wall Beam

Abstract

AbstractThe transient thermal process of a thin-wall beam with CO2Gas Metal Arc Welding (GMAW) is analyzed by Finite Element Analysis Method (FEA). The thermal input is simplified as transient section body heat sources and loaded as its actual sequence in the analysis. The transient temperature field obtained can represent the basic characteristics of the real welding process and can be used as the foundation of thermal elastic-plastic analysis. Based on the temperature field, thermal elastic-plastic FEA is performed on the thin-wall beam. The distribution and change of the welding deformation, stress and strain are obtained and compared with the experiment results. Also an improvement can be presented on the inherent strain method. Using the inherent strain method, the welding deformation of the thin-wall beam is calculated. The temperature loading method is developed to load the variable inherent strain value expediently. The loading of inherent strain value on spatial welding line that is unparallel to the global coordinate axis is achieved with the application of element coordinate system. Comparison with the experiment results shows that both the thermal-elastic-plastic analysis and inherent strain analysis method can be used to predict the welding deformation effectively, the results calculated by both the thermal-elastic-plastic analysis and inherent strain analysis are close to the test measure results.