Rational design of pin puller and its closed bomb test-based equivalent testing

A pyrotechnically actuated pin puller is considered an efficient and important separation device because of its advantages of low pyroshock and no debris. However, its large size, complicated structure, and difficulty in performance testing hinder the large-scale application in weapon systems. Herein, we report a new pin puller structure with the gas inlet channels designed on the pin shaft. The novel design achieves the combination of the initiator and the pin shaft and reduces the size of the pin puller by 2 cm. A mathematical model of the movement process of this pin puller is established and further used to predict the variation rule of performance parameters. In particular, equivalent testing based on a closed bomb test (CBT) is proposed to examine the internal pressure of the pin puller calculated using the model. The experimental results of the equivalent testing are indeed consistent with the model simulation results and readily used to optimize the pin puller further in terms of the sensitivity analysis results of design parameters. The results show that our CBT-based equivalent testing can provide a facile way for the examination of the pressure of pyrotechnically actuated devices.