Design and Impact Simulation of High-G Acceleration Switch

The facts of rapidly deepened applications and progressive techniques of micro-electro-mechanical systems (MEMS) attract many organizations and engineers devoting to the research of microsensors and microactuators, among which microaccelerometer and microgyroscopes are successive examples. An acceleration switch is a kind of accelerometers. As the applied acceleration beyond a threshold value, the switch will latch up and output a triggering signal. The acceleration switches made by MEMS techniques possess enormous commercial benefits due to its numerous advantages, such as low cost, miniature volume, high reliability, and reusability. It can also be widely applied in many industries such as airbags, crash recorders, and monitoring the cargos during shipping. This thesis designed and numerically simulated a high-G acceleration switch subjected in high-G impact environments.
In this thesis, we aimed to design an acceleration switch which could resist impact with a threshold acceleration of 2000G. The mechanism of switching was designed by CAE software package, and the dynamic response was simulated using LS-DYNA. The goal was to examine whether the acceleration switch could function well to meet the impact specification of MIL-STD 883E. If there had any faults such as stress concentration or defects of structure, the design was changed immediately to reduce the research time and the cost before trial production or mass manufacture.
The results of the simulation dictate that the proposed acceleration switch can function well with the acceleration threshold of 2000G, and the latch mechanism works successfully and stays in the latched position. Besides, the contact components keep in touch, and all the components work properly without any failures. Under the impact load of 1800G, the latch mechanism cannot be latched properly, and the contact component cannot be in contact. We conclude that the proposed acceleration switch can work when the applied acceleration is beyond the acceleration threshold.