Applying a Highly Precise CAE Technology Component Model Automotive Bolt-Loosening Mechanism

In this study, the authors apply their highly precise Computer Aided Education (CAE) technology component model to explain the bolt-loosening mechanism in automotive parts that are secured with nuts and bolts—a problem that plagues manufacturers. This was accomplished by first visualizing the situation during prototype testing and then using CAE to accurately describe the problem. Specifically, three types of bolted pieces, each with a different pitch, were subjected to a prototype test in order to visualize their dynamic behavior along with changes in the amount of axial force applied to the bolted parts. And then, in conducting a high quality CAE analysis, the first step is to define the problem that needs to be solved and then model it using some kind of numerical formula. A computer is then used to analyze the model using an algorithm (calculation procedure). The appropriateness, applicable scope, and performance of the algorithm itself are developed based on theory, and the computer technology (calculation technique) is able to actually perform the calculations. The analysis verified that uneven stress on nut-bearing surfaces in particular was a primary cause of loosening on parts secured with nuts and bolts. In conclusion, this study applied the highly precise CAE technology component model to explain the problems associated with the loosening of parts tightened with nuts and bolts as well as to clarify the mechanism involved in similar types of technical problems affecting the auto industry. The desired results were obtained.