Numerical Simulation For Forming Process Of Round-Point And No-Rivet Clinch Of Magnesium Alloys

Nowadays, lightweight construction strategies of automotive have become an inevitable trend in automotive industry. Thanks to premium properties, magnesium alloy has very broad prospects. However, due to the limited forming capability of magnesium at room temperature, the traditional mechanical joint method and welding are difficult to achieve high-quality connection. Round-point and no-rivet clinch is often called clinching, it is an innovative connection technology, but magnesium alloy is heated to a suitable processing temperature requires a longer time that limit the application of magnesium alloys. How to reduce the heating time to a reasonable extension becomes a key factor in the application of magnesium alloys, it has a very significant research meaning.Firstly, the problem that longer heating time in the traditional round-point and no-rivet clinch of magnesium alloys is analyzed. Then, according to contradiction matrix method of TRIZ, the structure of traditional die is improved and the spring is used as movement mechanism of new die.Secondly, finite element model is established and assembly on UG software, which build a foundation for the next steps. The FE-simulation is done based on the heat transfer module of Deform-3D. The result show that new die decrease the heating time to 1s or less, instead of 3-6s with conventional round-point and no-rivet clinch methods.Finally, the finite element simulation of the joining process is carried out on Deform-2D. After analyzing stress-strain curves and load-stroke curves of punch, the result show that, stress and strain are mainly concentrated on the top alloy under the punch and interlock parts of alloys. Compared simulations are earred out, which models based on process parameters and geometric parameters. The mechanism of the effects was explained, which can provide references for further optimization of parameters of round-point and no-rivet clinch.