Numerical Analysis of Self-Pierce Riveting of Magnesium Alloys

Abstract

Regulations all over the world have been pushing vehicle manufacturers to increase fuel economies and decrease green house gas emissions. An effective way to meet these new regulations is to reduce automobile weight through the use of lightweight metals. Magnesium alloys have received recent interest due to its high strength-to-weight ratio. However, conventional fusion joining methods such as resistance spot welding are not effective for magnesium alloys. As such, an attractive joining technique for these lightweight metals is self-pierce riveting (SPR) which is fast, fumeless and does not melt the material. However, SPR must be performed at elevated temperatures because of the low ductility of magnesium alloys at room temperature. Even though the SPR joining process has been established on magnesium alloys, this joining process is not optimized. As such, this study establishes the first attempt at simulating the SPR of magnesium alloys through the use of the finite element method. An internal state variable (ISV) plasticity and damage material model was employed and comparison to experimental results show good results. The results of this study show that the ISV material model is ideally suited for modeling the SPR in magnesium alloys.