Simulation of the Axial Cutting Deformation of AA6061-T6 Round Tubes Utilizing Eulerian and Mesh-Free Finite Element Formulations

摘要

Experimental and numerical studies have been completed on the deformation behavior of round AA6061-T6 aluminum extrusions during an axial cutting deformation mode employing both curved and straight deflectors to control the bending deformation of petalled side walls. Round extrusions of length 200 mm with a nominal wall thickness of 3.175 mm and an external diameter of 50.8 mm were considered. A heat-treated 4140 steel alloy cutter and deflectors, both straight and curved, were designed and manufactured for the testing considered. The four blades of the cutter had an approximate average thickness of 1.00 mm which were designed to penetrate through the round AA6061-T6 extrusions. Experimental observations illustrated high crush force efficiencies of 0.82 for the extrusions which experienced the cutting deformation mode with the deflectors. Total energy absorption during the cutting process was approximately 5.48 kJ. Further testing, considering extrusion lengths of 200 mm and 300 mm which resulted in progressive folding and global bending deformation modes were also completed which illustrated crush force efficiencies of 0.66 and 0.20 respectively. Numerical simulation of the axial cutting deformation process followed by contact between the cut petalled extrusion side walls with either the curved or straight deflector were simulated by employing Eulerian and Smoothed Particle Hydrodynamic (SPH) mesh-free methods. Good predictive capabilities of the numerical model employing the Eulerian element formulation were observed and were important towards the understanding of the contribution of deformation mechanisms and friction towards the force/displacement response of the extrusions in the cutting deformation mode with the presence of curved or straight deflectors.