A Smoothed Particle Hydrodynamics Approach for Efficient 3D Process Modeling of Linear Friction Welding

Abstract

Linear friction welding (LFW) is a solid-state joining process in which a weld between two metals is formed by combined action of heating via plastic deformation and forming force that creates a weld interface. The technique is increasingly attracting attention in aerospace industry, due its several advantages like absence of solidification defects, no requirement for external heat source, and the mechanical and fatigue properties of the weld being equivalent or surpassing the parent material. Due to large deformation, commercially available software tools are limited to modeling of LFW in 2D using Finite Element Method (FEM) with adaptive mesh controls. In this work, we developed a meshless approach that utilizes Smoothed Particle Hydrodynamics (SPH) to obtain a physics-based model capable of capturing the thermo-mechanical behavior LFW process in 3D. The meshless framework is implemented using a commercial finite element analysis package using custom defined application programming interface. Subsequently, we employed the developed model to simulate and investigate flash formation and burn-off distance of LFW of Ti-6Al-4V workpieces. The SPH simulation results agreed well with FE simulation and experimental data. The model demonstrated computational efficiency of approximately 16 hours to simulate 3 seconds of LFW process with a 12-core desktop workstation. This work was undertaken under a SBIR Phase II program funded by The U.S. Air Force, Contract FA8650-19-C-5050, awarded to ACT, Inc.