Force characteristics of self-piercing riveting

Abstract

Self-piercing riveting (SPR) is a high-speed mechanical fastening technique for point joining of sheet-material components. SPR is becoming important in automotive applications for aluminium vehicle body assembly. However, compared with current sheet-metal joining processes in the automotive industry, SPR requires a substantially higher operating force. Reduction of the operating force is one of the key objectives for enhancing the mobility and applicability of the SPR system. In this research, the force characteristics of the SPR process were studied with the aim of reducing the operating force. The effects of various workpiece temperatures and thicknesses and the mechanical properties of the SPR joints were examined. It was found that the operating force of SPR was determined by the rivet deformation force. Under certain process conditions, an increase in temperature in workpiece material could help decrease the operating force as it permits the use of softer rivets.