Highly Accelerated Stress Screen Modeling And Simulation Of Aerospace Precision Electromechanical Component

Throughout the trend of global development in the 21 st century, the increasingly mature of aerospace technology has not only playing an important role in the study of scientific research, but also acting as a symbol of comprehensive national strength for country and nation. However, spaceflight accidents happened occasionally in recent years. As a consequence, scientists have to solve the problem urgently that how to make aerospace components work securely and stably,while the actual simulation test of aerospace components is quite difficult due to the high cost and complex working conditions. At this moment, most of the researches are limited to theoretical study and specific standards and specifications have not been formalized yet. Highly Accelerated Stress Screening(HASS) is of high efficiency for reliability test and commonly used in the production stage. In order to maximize the reliability without consuming the normal life of products, we can discover the internal defects of components quickly by using computer finite modeling and simulation technology, and then take effective measures to modify and eliminate the defects.This paper takes the aerospace electromechanical components as the research object which is based on an engineering project of institute. The main contents are as follows:1. It introduces the principle of Highly Accelerated Life Testing and HASS, then expounds the related theory of computer finite element, especially the analysis of thermal and dynamic. According to the calculation method of acceleration root mean square, the typical military specifications power spectrum density curve can be converted into the order of vibration magnitude.2. According to the reliability test of the aerospace electromechanical component, this paper presents the finite element simulation under the comprehensive environmental conditions based on the fundamental principle of HASS. The electromechanical components’ geometric model and finite element model are established. In the models, the pin and the solder joints are equivalently considered as beam elements and solid elements.3. The random vibration loads and gradient temperature loads are applied to the finite element model of the electromechanical component. And the constraints are confirmed by the specific requirements of HASS testing. Several different solvers are utilized respectively to complete the temperature step stress simulation, rapid temperature changing simulation, random vibration simulation and comprehensive stress testing simulation.4. The comparison of simulation results with testing results shows that the simulation process of the electromechanical components is reasonable and effective. It can significantly reduce the loss of the product and the testing time in HASS testing. By using the reliability analysis method, the range of test conditions can be refined and the final HASS profile is obtained.