CAE Applications and Techniques used in Calculating the Snaps Insertions and Retentions Efforts in Automotive Trims 2014-01-1032

A snap-fit is a form-fitting joint, which is used to assemble plastic parts together. Snap-fits are available in different forms like a projecting clip, thicker section or legs in one part, and it is assembled to another part through holes, undercuts or recesses. The main function of the snap-fit is to hold the mating components, and it should withstand the vibration and durability loads. Snap-fits are easy to assemble, and should not fail during the assembling process. Based on the design, these joints may be separable or non-separable. The non- separable joints will withstand the loads till failure, while separable joints will withstand only for the design load. The insertion and the retention force calculation for the snaps are very essential for snap-fit design. The finite element analysis plays a very important role in finding the insertion and the retention force values, and also to predict the failure of the snaps and the mating components during this process. The snap insertion and retention simulation is highly non-linear, due to the non-linear material behavior and contact between the mating components. This paper explains the various techniques and methodology used to predict the snaps insertion, and the retention force for different types of snap-fits.