Clinchen von Stahl- und Aluminiumblechen größerer Dicke

Abstract

The researchproject focuses on the development of basic principles, which allow the industrial use of clinching in thick sheet applications. Ostensible this includes the determination of performance characteristics for an economic and reliable production of clinched joints using an overall sheet thickness range of 8.0 mm to 16.0 mm, which is typical for perspective applications in structural steelwork or railway and commercial vehicles. The clinching process, the potentials and limits as well as the required tooling and process design are investigated systematically for this thickness range. The needed tool geometries are developed using experiment and FEM calculation taking into account the limiting factors and process characteristics required. The focus of research is on steel connections, but also knowledge of steel-aluminum compounds and pure aluminum compounds is worked out. Besides the influence of tool dimensions (punch and die geometries) to the joint geometry, relevant knowledge is carried out by strength tests and a cost assessment compared clinching and welding. Additional an evaluation of the numerical process description and of the joining induced warping is done. With regard to the determination of appropriate tool sets, strong deformation and thinning of the neck using small tool dimensions as well as high joining forces using large tool dimensions limit the target area for the connection design. Since the dimension of the tools for increasing total sheet thickness must be at least tend to also be larger, joining force significantly exceeding 100 kN is required. Depending on the point size, sheet thickness and sheet strength, this force can even reach 1.000 kN. The ratio of the required joining force and the maximum shear strength of the joints is approximately in the same dimension as in thin sheet metal clinching applications. In addition to the basic possibility of clinching thick sheets the project prove the transferability of known positive process characteristics: high cyclic stability, low warpage and component cost in mass production. Thus, the major advantages of clinching compared to thermal joining processes for the thick sheet processing industries are available