Small Caliber Artillery Fuses Magnetorheological Fluid Delay Arming Mechanism Characterization

Magnetorheological fluid delay arming device applys MRF to the fuze safety systems with its advantages high accurate arming delay distance, high safety and simple structure.While the research of MRF properties and the application in the small caliber fuze is still in the initial stage, this dissertation use theoretical analysis, dynamic simulation and test verification to investigate the application of the magnetorheological fluid in fuze delay arming device especially in the small caliber fuze,the main contributions of this dissertation include the followings:1、Focused on the difficulties of the short arming delay distance, the limited design space for small caliber fuze delay arming device, designed a new kind of small caliber fuze delay arming device. Furthermore, some checks and optimizations on the main components were done.The sizes of the permanent magnet was obtained based on the theory of magnetic circuit design and the numerical simulation results were illustrated to prove the validity.2、By analyzing the physical model of MRF leakage, the delay arming time model of the MRF fuze was set up based on the theory of fluid dynamics. The data of the test and the flow field simulation results have proved the correctness of the leakage time model. Through the simulation of Matlab software,the relation curves between the delay arming time and some factors were derived.3、Designed a series of tests on the MRF for fuze:(a) tested the MRF viscosity and shear stress characteristic under different shear rate in zero field;(b) tested the characteristics of different configuration of MRF,the test results provided the basis for the proportion of future MRF;(c) by making the centrifugal sedimentation comparative experiment on MRF for fuze and the common MRF, found out that the sedimentation stability of MRF for fuze was better than common MRF;(d) the temperature and humidity test, low temperature test were carried out on MRF for fuze, results indicated that the temperature and humidity environment had certain influence on performance of MRF.and the low temperature almost had no effect;(e) the reliability grope tests of MRF adopted the way of step-temperature,the test results offered the temperature stress for the accelerated life tests of MRF.4、By analyzing the consistency and the acceleration of MRF failure process, the accelerated life tests scheme for MRF is feasible.And use the modified Powell algorithm to deal with the accelerated life test data.Finally, the main work in this dissertation are summarized,the innovation points are introdeced,the future research work are proposed.