Analysis of Shock Loosening of Connecting Screws of an Electronic Equipment

Threaded connection is widely applied to airborne electronic equipment. The screws attached to the isolator are loose in the shock test of some equipment. This paper firstly puts forward the macroscopic reasons for the loosening of the device screw, mainly because the shock response is too large and the connecting screw is too small. Through the simulation analysis, it is found that the screws need to be increased to at least M10 to meet the strength requirement. Considering the simulation error and the strength margin, the improvement measure of replacing with larger-damping isolator is put forward, and the improved equipment passes the shock test successfully. The reason analysis and improvement measures for screw loosening in this paper are useful for the selection of screws and isolators of the same type of electronic equipment.