Equivalent modelling strategy for a clinched joint using a simple calibration method

Abstract

Clinching is a mechanical joining technique that involves severe local plastic deformation of two or more metal sheet parts resulting in a permanent mechanical interlock. Today, it is a reliable joining technique used in heating, ventilation and air conditioning (HVAC), automotive and general steel constructions whilst still gaining interest. As it is not computationally feasible to include detailed sub models of these type of joints in FE simulations of clinched assemblies during the design stage, this paper proposes a simple methodology to represent these connections with simplified elements. The key point of the method is the use of uncoupled plastic behaviour to model the joint plastic properties. In order to calibrate the parameters governing the equivalent model, a simple shear lap and pull-out reference test of a single clinched joint was used. The presented methodology is validated using a modified Arcan test of a single joint, which enables to exert a combination of shear and pull-out loads. Finally, a peel test is conducted to study the influence of bending moments on the behaviour of the joint.

Mechanical Behaviour of Clinched Joints in Configurations

“…To calibrate the equivalent model as proposed by Breda et al [7] (Figure 1), a H-tension test and a shear lap test were executed with the considered material and tool combination. The displacements of the specimen were captured using an extensometer.…”

“…This knowledge is important to serve as a basis for design rules for clinched joints in structures which can help to establish the joining technique in structural design. A first step of a design strategy was proposed by Breda et al [7] were an equivalent model for a single clinched joint was investigated, to reproduce the deformation behaviour of a single clinched joint. For the calibration of this model, a simple shear lap and pull-out test was sufficient.…”

Wear of Shaped Surfaces of PVD Coated Dies for Clinching

“…The sheets being joined are overlapped and plastically deformed by moving the punch against the sheets to produce an interlock that fastens the sheets. The formation of the interlock is controlled by the die, the shape of which determines the material flow during the joining process [7,31,59].…”

The effect of sheet metal anisotropy on the calibration of an equivalent model for clinched connections

“…Therefore it is important to investigate the possibility of an equivalent model for clinched joints. An equivalent model for clinched joints was proposed by Breda et al [6]. Although this model provided good results on DC01 (low carbon steel sheet), more research was needed to examine the potential of the methodology.…”

“…Some factors which need to be considered are the effect of sheet metal anisotropy and residual stresses on the calibration step of the equivalent model. In order to fully understand the goal of this paper the key points of the method [6] are summarized briefly. The proposed equivalent model consists of a connector element with 6 degrees of freedom and a kinematic coupling which connects the connector element with the shell elements of the sheet material.…”