Combining a high-speed mechanical joining technique with the attachment of functional elements in automotive structures

Abstract

The implementation of lightweight materials such as modern wrought aluminium and casting alloys enables a significant reduction of the vehicle’s total mass. The extended use of lightweight aluminium castings and extrusions offers considerable potential for weight reduction. The cost-effective joining of these aluminium structures is challenging the conventional thermal and mechanical joining techniques. The paper details the development of a new type of mechanical functional element based on the principle of high-speed joining. Functional elements also know as fuctional attachments are normally attached separately from the fixings which used to join two or more sheets of material. Examples for fuctional elements are brackets, clips and fixing studs. The objective on this paper based project is the further development of the high-productive joining method high-speed joining to integrate a functional element into the joining process. For this, a modification of a given joining element geometry has to be developed that allows the transmission of high-torque moments and reaches high-push-out forces. Therefore, several geometries were developed and optimised with simulations and experimental investigations. The results show that the joining element based on the technology of high-speed joining can meet the requirements of metric aluminium stud-threads with diameters up to 6 mm and steel stud-threads with diameters up to 5 mm.