Numerical simulation research on welded residual stress and distortion of aero-engine afterburner lobe mixer with different welding sequences

Abstract

Most thin-walled parts of aero-engines with intricate surfaces, such as lobe mixer, are welded using tungsten inert gas (TIG), which will certainly induce stress and distortion, causing a serious in uence on assembly accuracy. The objective of this study was to establish a nite element model to optimize TIG wire ller welding sequence for an aero-engine lobe mixer composed of GH3044 nickel-based superalloy at the thickness of 2 mm. A new method for optimizing residual stress and deformation in the welding of large-size components was proposed.We carried out a 2 mm thickness plate TIG wire ller welding experiment to obtain the ideal process parameters and validate the heat source model and thermal boundary condition, and also designed a set of frock clamp.The stress and distortion of the lobed mixer were analyzed under various welding sequences based on the established nite element model. The results of the study showed that the peak residual stress difference of the lobe mixer is smaller using such a xture. Different welding sequences affected the stress uniformity throughout the structural member. The symmetrical welding of single weld was a better process, with a peak distortion of only 0.54 mm and uniform stress distribution.