Simplified Spot Weld Model for NVH Simulations

NVH simulations of structures with a large number of spot welds require simplified models for the spot welds. The simplified models should be able to deliver reliable natural frequency and vibrational mode. Sometimes the damping of the spot-welded joints is to be considered as well. It may also be desired that the same spot weld model can be used for fatigue predictions so that a uniform spot weld model can be employed for both applications. This paper will present such a model. The model is based on shell element models like automotive structures with coarse and non-matching meshes and it is verified by the experimental results on coupon and component levels. The model consists of a beam element connected through rigid bars to the shell elements of the basic structure. An automatic generation of such spider models in large structures is supported by some mesh generators like MEDINA and ANSA. Application of the model in fatigue predictions is briefly discussed as well.