Research On Low Shock Trigger Used On Large Load Flywheel Nut Separation Mechanism

With the rapid development of space technology, the new payload is more and more widely used in extraterrestrial space, especially in sensitive devices and optical devices which is increasingly sophisticated, diverse and flexible. Such payload is very sensitive to shock and vibration environment produced by in orbit release. However, the most common used pyrotechnic actuator means will inevitably have a significant impact and chemical contamination during release. Therefore, the development of new non-pyrotechnic separation technology is in the pipeline. At present, the most achievement of non-pyrotechnic technology focused on the areas of smart materials. Shape memory alloy, as the material of the earliest research in this field, has achieved abundant research results. In this paper, we developed a low-impact, high load, fast response and the separation device with the shape memory alloy which can be reused for the heavy load release in orbit.Aiming at the requirements of low impact and fast release of heavy load in orbit, this paper promated the design of separation mechanism and analyzed the typical detachable connection form used for large load in aerospace and proposed a new design scheme of separation device using flywheel nut and shape memory alloy, and on this basis we developed the detailed design and computing of the mechanical components and shape memory alloy trigger.Based on the material properties of shape memory alloys, this paper carried out the modeling and experiment of the trigger components. Combined with the constitutive relations and typical boundary conditions of shape memory alloys, the thesis derived of the one-dimensional state relation of "stress-strain-temperature". Based on the actual need of drive performance, this paper determined the basic response performance and the key design parameters by driven characteristic experiment with specified test system.Combined with the design requirements for the basic characteristics of the separation mechanism, the thesis facilitated the characteristic verification of the device by simulation and prototype experiment. By static analysis, it is achieved that the response with statics structural strength and deformation under preload meets the requirements. With the dynamic simulation of the mechanism movement and the prototype release test, the basic unlock functions were verified. And the thermal response characteristics of mechanical pairs and the whole device is tested by thermal simulation and prototype thermal experiment.