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Self Pierced Rivets (SPRs) are being used in the automotive industry with aluminum structures due to their superior functional qualities and assembly processes. Fatigue behavior of SPR connections needs to be investigated experimentally and numerically to predict SPR fatigue lives. Testing of aluminum lap-shear and coach-peel coupons is performed to obtain the fatigue lives of SPR connections under different conditions. A damage model of the SPR fatigue life is developed using a global-local approach. The damage model is then validated using T-box structures with different loads and gauge combinations. The fatigue lives of aluminum car bodies are predicted using a Ford-developed tool based on the damage model.

Fatigue life predictions using the strain-life method are used in the design of modern light weight vehicle, for the complex loading that occur with the structural durability tests that these vehicles undergo. The accuracy of these predictions is dependent upon the many factors; geometry, loads & materials etc. This paper details a new procedure to ensure the quality and accuracy of the material parameters for the fatigue life prediction software. The material parameters for the solver are obtained by performing strain-controlled fatigue tests. The geometry of the coupons tested is determined by size and thickness of the material specimen that they are machined from and the loading regime in the test. Detailed data analyzed is conducted on these tests and the parameters that are used as input into the CAE strain-life fatigue prediction software are generated.

Effective use of adhesive bonding in automotive vehicle bodies requires analytical methods for durability, so that potential fatigue problems and unnecessary overdesign may be eliminated before the physical prototype stage and release of product with unquantified safety factors avoided. This paper describes a fracture mechanics-based method for predicting the durability of adhesive joints, based on work previously carried out at Volvo [1]. The method requires relatively modest modifications to a typical vehicle body FE mesh. Adhesive bonds are represented by bar elements around the periphery of each bond. Grid point forces from shell elements adjacent to the adhesive bond are recovered and used to determine line forces and moments at the edge of the glued flange. These forces and moments are then transferred to an analytical sandwich model of the joint.