Clinch-Bonded and Rivet-Bonded Hybrid Joints: Application of Damage Models for Simulation of Forming and Failure

Abstract

The aim of this work was to simulate the failure behaviour of clinch-bonded (CB) and rivet-bonded (RB) joints using the finite element method (FEM). The Gurson–Tvergaard–Needleman (GTN) model and a ductile damage (DD) model were used as possible alternatives to simulate damage and failure of the rivet and plates, while a cohesive zone (CZ) model was employed to simulate damage and failure in the adhesive layer. The analyses were conducted using Arbitrary Lagrangian–Eulerian (ALE) adaptive meshing to avoid excessive element distortion and mass scaling to increase the minimum time increment in explicit analyses. The analyses started from three-dimensional (3-D) modelling of the rivet or clinch forming processes. Afterwards, the GTN and DD model parameters were derived using an inverse method, fitting the numerical results of simple joints (riveted, clinched) with experiments or literature data. Finally, the adhesive layer was introduced as a layer of cohesive elements. The parameters of the CZ model were determined in previous work on the adhesive. The results of the analysis were applied to the RB and CB joints, and good agreements with the corresponding experiments were found concerning the stiffness, peak load and energy absorption of the joints. The authors concluded that different damage models, tuned with experiments performed on simple joints (riveted, clinched or adhesively-bonded), can be combined in a unique model to simulate effectively the failure behaviour of hybrid RB and CB joints.

Keywords:

• HYBRID JOINTS
• FAILURE
• DAMAGE
• FINITE ELEMENT MODELLING