Loosening analysis for fastening screw of automotive door trim parts

• Published in: International journal of automotive technology Vol. 17; no. 4; pp. 671 - 679
• Main Authors: Yang, S. M., Yoo, S. H., Gi, D. S., Choi, S. B., Kim, K. S., Jeong, N. T., Choi, S. U., Suh, M. W., Lee, J. H.
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Society of Automotive Engineers 01-08-2016; Springer Nature B.V
• Subjects: Analysis; Automobiles; Automotive components; Automotive Engineering; CAE; Computer aided engineering; Doors; Engineering; Fasteners; Friction; Injection molding; Load; Loosening; Mechanical engineering; Mechanical properties; Metals; R&D; Radiation; Research & development; Screws; Studies; Trim; Vehicles; Degradation; Screw; Loosening; Plastic fastening parts; Clamping force
• ISSN: 1229-9138; 1976-3832
• DOI: 10.1007/s12239-016-0066-1

While a screw is a fastening element that can tighten the two parts at low cost, the loosening of the screw is generated due to external forces such as repetitive load, vibration, and thermal stress. This phenomenon decreases the initial clamping force, and this can be a serious problem to the safety of the product. However, while fastening parts are handled through experiment and experience, there is a lack of research on the screw loosening of plastic fastening parts. For example, vehicles have various fastening parts. Among the fastening elements, screws are typically used for tightening parts of the vehicle door trim. Vehicle interior materials are mainly composed of plastic parts. Especially, the temperature of the vehicle interior changes from a sub-zero temperature to 100 degrees (°C) due to solar radiation. Unlike metals, plastic materials are commonly susceptible to the environment. In this study, the fastening screw of automotive door trim parts is selected. First, a screw loosening mechanism is implemented through Computer Aided Engineering (CAE) analysis and the influences of degradation are then analyzed. Secondly, the selecting method of clamping force is suggested through the analysis result of reduction according to the tightening torque.