Getting optimum design for rib supported standard beam type snap fit structures by using finite element analysis method

In this study, assembly methods for plastic products which are used almost all areas and snap fit assembly method which is one of the most economical, easiest to produce and most suitable methods are examined. Factors which affect the snap fit performance are examined and relationships between these factors with assembly force and mechanical strength are explained by equations. These equations are only acceptable if standard beam type snap fit is used. In this study, assembly force and permanent deformation situation for angled and rib added snap fit type are examined for different kinds of materials. For this study `ANSYS Workbench 12? structural analysis module is used. Mesh structure of the model is generated by using automatic fine mesh settings of the finite element analysis program. Plastic materials which are mostly used and have different mechanical strength are chosen for snap fit models subject to the structural analysis. Thus it is easy to determine which snap fit design should be used for a specified material. Materials which are used for the structural analysis process are polypropylene with 10% talc (PP TD10), polycarbonate (PC), PC/ABS blend and PBT with 20% glass fiber. Structural analysis in this study is performed by assuming that the products are at the room temperature (23°C). Snap fit design parameters are beam thickness, width, length and displacement. In this study there are 108 snap fit design and 4 kinds of materials. So total 432 structural analyses are performed for this study. During the reading of the analysis results, first of all it is examined that if the strain value is higher than the maximum strain limit of the material or not. After that for suitable design and material combinations, classification is performed according to the required force for specified displacement value.