Abstract: Based on the general stress intensity distribution of a broad interference theory and reliability model of a single failure mode, the torsion spring reliability optimization model was established under multi-failure mode. The normalized weighted method was used to solve the torsion spring reliability calculation under equal failure effect mode and unequal failure effect mode. Under given structure and constraint conditions of torsion spring, the best reliability optimization of torsion spring structure was done in the same failure mode (equal failure effect) and different failure mode (unequal failure effect) one using the proposed model and techniques. Under equal failure effect and unequal failure effect, compared with the torsion spring reliability of non-optimized structure, the proposed reliability optimization models and methods proposed are reliable, valid and good reference for the reliability optimization of the spacecraft components.

Key words: Torsion spring, Failure mode, Reliability, Optimization, Deployable mechanism, Satellite