Meshless analysis of a snapping and unsnapping action, using LS-DYNA

One of the products manufactured by Elkamet Kunststofftechnik GmbH for both the automobile industry and the lighting industry is extruded profiles made from polymer materials. The analyses carried out involved investigation of a seal developed by Elkamet that was located between a car front windshield and a water reservoir, with the specific aim of investigating the snapping shut and unsnapping of a clip connection. It was essential that the forces to be applied be defined across a severely deformed rubber sealing lip.

The results facilitated comparison of the forces that arose in snapping shut and unsnapping the three geometric variants investigated, thereby assisting the customer in selecting the most suitable variant in terms of serviceability.

The analysis of the snapping shut and unsnapping was carried out using LS_DYNA. Due to the way the rubber lip became severely deformed during the operating sequence, a meshless method (the element-free Galerkin method) was used for the calculation performed within ANSYS LS_DYNA. Meshless methods are numerical methods that use weighted nodes rather than finite elements for spatial discretization. Such methods are particularly employed in cases involving large deformations. The analysis facilitated determination of the forces required to snap and unsnap the cover on the water reservoir. The investigation involved the examination of three different geometric variants.