Clinching is a mechanical joining technique that involves severe local plastic deformation of two or more sheet metal parts using a punch and die. The local deformation results in a permanent mechanical interlock. It is widely applied as a reliable joining technique in automotive, HVAC and general steel constructions and is still gaining interest . In the search for lightweight constructions, clinched joints are often used to join dissimilar materials which are hard to weld. With no additional materials added to create the joint (bolt, rivets, welding material) this joint can create a lightweight alternative for conventional joining techniques.
Because of the geometrical complexity of the joint, the material state varying from point to point [1] and different tool geometries, it is complex to predict the mechanical behaviour of the joints. Limited studies are performed to characterise the mechanical behaviour of clinched joints in group configurations [2, 3] . To this day, construction rules for clinched joints are not yet developed, despite the gaining interest for the joining technique. In this paper, the mechanical behaviour of multiple clinched joints under mixed-mode loads (peel, shear and pull-out) is investigated using a modified Arcan test. The experimental results are compared with a proposed equivalent model for clinched joints [4], to validate if the model can reproduce the deformation behaviour up to maximum force. The theoretical maximum resistance force of the configurations are then compared to the experimental maximum resistances to investigate the influence of possible interaction effects on the maximum strength of the configuration. This study is part of a global design strategy for clinched joints in large structures. The results of this work can serve as a base to define general construction rules for clinched joints for several applications.
[1] S. Coppieters, Experimental and numerical study of clinched connections, Ph.D. thesis, KU Leuven (2012).
[2] R. Davies, R. Pedreschi, B. Sinha, Moment-rotation behaviour of groups of press-joins in cold-formed steel structures, Thin-Walled Structures 27 (1997) 203 - 222.
[3] R. Pedreschi, B. Sinha, R. Davies, End fixity in cold-formed steel sections using press joining, Thin-Walled Structures 29 (1997) 257 - 271.
[4] A. Breda, S. Coppieters, D. Debruyne, Equivalent modelling strategy for a clinched joint using a simple calibration method, Thin Walled Structures113 (2017) 1 - 12.
