Prediction and isolation of pyroshock in typical pyrotechnic device based on coupled modeling technique

In this paper, a typical piston pyrotechnic device was designed and the thin-walled circular tube was used as the energy absorber to isolate pyroshock. To provide accurate load and simulation results, a coupled numerical model linking propellant combustion and finite element analysis was established. A shock experiment for the typical pyrotechnic device was carried out to verify the correctness of the coupled model above. Further, the buffer performance of the thin-walled circular tube was investigated. The simulation results reveal that the maximum shock overload with the study case was reduced from 670,000 g to 20,000 g. The coupled model is capable of obtaining accurate dynamic load and accurately guiding the simulation in comparison with commonly utilized pyroshock prediction methods. For loads of varying precisions, the energy absorption rates of thin-walled circular tubes are similar with a maximum difference of 4.1%, while other buffer performance and stable appearance are drastically different. Furthermore, the influence of the thermal field is not taken into account in this paper, and the thermal-solid coupling based on the established coupled model is the next research topic. •Accurate dynamic pressure load shocking the pyrotechnic device can be obtained by the coupled model.•The coupled model connects the mechanical interaction in finite element analysis with propellant combustion.•The energy conversion of the coupled system and two sub-systems is captured and used for error analysis.•The influence of different precision loads is investigated and the coupled model results are the most consistent with reality.