Research On The Release Device Based On Shape Memory Alloy

This paper describes the designation of a (Shape-Memory Alloy) SMAconnection-disconnection device with low impact and speedy response by utilizingthe shape memory effect of shape-memory alloy. The background of the paper is theseparation of non-pyrotechnic devices in spacecraft and underwater vehicle payload.With theoretical study, experiment, simulation and other research approach, this paperinvolves the following tasks:First， this paper analyzes the separation process of several typical SMAconnection-disconnection devices from home and abroad, and summarizes the basicsof how SMA drives the device. Based on the SMA constitutive model, the SMA drivemodel and the model of electric heating have been established. The time-temperaturecurve of SMA electric heating with MATLAB has been simulated; the d iameter andheating current of SMA wire, and the effect of SMA wire’s convective heat transfercoefficient on SMA wire’s heating rate have been analyzed.Second, this paper analyzes the effect of pre-response, current flow, and constantload on the recoverability of SMA by testing the transition temperature, recovery rate,maximum recoverable strain, and load response—key factors measuringrecoverabilityThird, this paper designs connection-disconnection device with the combinationof SMA wire with separation nuts. By optimizing the trigger mode of SMA wire sothat it needs only smaller trigger force, this paper intends to design aconnection-disconnection device that can realize detachment within200ms with20kN pre-load. By analyzing the forces on split nuts and locked components, parametersof split nuts, drive spring, safety spring, release spring, and SMA wire have beenidentified.Finally, this paper has done numerical simulation for SMAconnection-disconnection device with LS-DYNA, and proved the feasibility of theSMA connection-disconnection device provided herein. When current flow is8A andthe preload20kN,numerical simulation of this device’s detachment time is87.12ms.