Parametric Study of the Centrifugal Insurance Mechanism in MEMS Safety and Arming Device

Abstract

MEMS (Micro-electromechanical Systems) becomes important increasingly due to the smarter and smaller fuze used in OICW (Objective Individual Combat Weapon). MEMS Safety and Arming (S&A) device is employed in different platforms and regions for small caliber projectile. Therefore, it is necessary to make a parametric study of the MEMS S&A device in different apply environments and explore the main sensitive factors of the MEMS S&A device to provide reference for designs. In this paper, based on the MEMS S&A device designed by our term, theory and finite element models are established, and the centrifugal insurance mechanism of the MEMS S&A device is parametric studied under the different speeds, temperature and thickness of the model by nonlinear dynamic method. By comparing the experimental and predicted results, the established FEM model is verified, and the conclusion is that the temperature and the centrifugal force are the main sensitive factors in the centrifugal insurance mechanism. In summary, we can suggest that the application environment, which the MEMS S&A device is suitable for, is the temperature equal to or slightly greater than normal temperature and the rotating speed higher than35000r/min of small caliber projectile.

Simulation and Test of a MEMS Arming Device for a Fuze

“…At present, research on MEMS arming devices is mainly focused on theoretical calculations and simulation analysis, and there is a lack of effective test verification, which leads to the bottleneck of MEMS fuze research, and few finalized products are applied in weapon systems [ 17 , 18 ]. A centrifugal arming device applied to small caliber grenades designed by Wang et al [ 19 ] is shown in Figure 1 , and its working principle is as follows: when the rotation speed reaches 30,000 r/min, the centrifugal elastic beam releases the first safety; when the projectile comes out of the muzzle and reaches a certain distance, the pin pusher pushes the shrapnel under the predetermined command to release the second safety. At this point, the arming slider continues to move in the locking direction under the action of centrifugal force until the head latch is locked by the cassette latch.…”

“…In addition, plastic deformation may occur under the action of centrifugal force in the shrapnel, resulting in the early release of safety. On the basis of Wang [ 19 ], Li [ 20 ] designed a long and thin structure of the centrifugal elastic beam, as shown in Figure 2 . This structure can obtain sufficient deformation when safety is released, but its strength cannot ensure the safety of service processing, and residual stress is easily generated during processing.…”

“…In view of the strength problems existing in the locking mechanism, shrapnel, and centrifugal elastic beam in the literature [ 19 , 20 , 21 ], the zigzag locking mechanism is designed in this paper, which does not need to set the microspring to increase the locking reliability and has the characteristics of high strength and high reliability. This structure can be processed by EDM process instead of the UV-LIGA process, which exhibits a greatly improved processing accuracy and yield while reducing the processing cost.…”