The deformation analysis of friction stir welding with different clamping distances for large thin-walled joints

Clamping scheme may change the local stiffness and affect the welding deformation which is very important for the large thin-walled joints connected by friction stir welding with heavy load and heat production. In this paper, the welding experiments of large thin-walled joints were conducted and the numerical simulation model is established based on three-dimensional stress mapping method. The accuracy of the numerical model is verified and welding deformation with various clamping distances is discussed. The restraint intensity index is employed to describe the influence of clamping distance on the stiffness of welding seam and welding deformation. The mechanism of welding deformation with the effect of clamping distance is well revealed by the analysis of welding stress and restraint intensity.