The mechanics and snap in force estimation of cantilever snap fit joint of lock plate by FEA

Abstract

Snap fit joints are widely used in industry for assembling different parts. Nowadays snap fits are found in wide range of application ranging from household appliances, toys, telephones to automobiles. This study is carried out to find the most accurate snap in force of cantilever snap fit by using finite element analysis. Snap in force is the most important term in design of cantilever snap fit because while in manual assembly process it is very much important to perceive the snap fit engagement. This study focuses on the nonlinear FE analysis method to calculate insertion force of the plastic snap fit part. Behavior of plastic material is nonlinear so it difficult and time consuming to calculate the snap in force by mathematical formulae only so nonlinear FE analysis will be best method to get the realistic snap in force value. This research work also included the mathematical model and linear FE analysis calculations for the estimation of snap in force. In nonlinear analysis contact, geometric and material nonlinearity is defined in the FE model. For the verification of the results the physical testing is also carried out with the help of force gauge tool. The analytical calculations and linear FE analysis estimates higher snap in force than the actual, while nonlinear FE analysis estimates more accurate snap in force value.