Influence of structural parameters on pyroshock protection performance of thin-walled circular tube—A study based on coupling calculation and orthogonal test

The prediction and protection of pyroshock are the focal issue in aerospace research. Historically, numerical approaches decoupled load acquisition from the system structural response, lacking comprehensive coupled calculations. This study develops a multi-physics coupling model integrating energetic material combustion, structural response, and transient heat exchange. Utilizing ABAQUS and its user subroutine, the lumped parameter method predicts impact load and flow field generated by energetic material combustion, while the finite element method simulates the pyroshock process and system structural response, addressing gas-solid heat transfer. A pyroshock experimental platform is built, and the accuracy of the coupling model is verified by comparing with the experimental results and classical case. Based on the coupling calculation results, the fluid-solid-thermal coupling in the pyroshock process is discussed. Then, an orthogonal test is designed to analyze the influence of structural parameters on the protection performance of thin-walled circular tube energy absorber. The results show that the multi-physics coupling model can capture the characteristic parameters of flow field, structure field, and temperature field, and effectively improve the calculation accuracy. Among the structural parameters of a thin-walled circular tube, the wall thickness has the most important influence, and its optimal value can improve the protective performance by realizing complete collapse and forming a multi-layer folding structure. In addition, both wall thickness and free travel show high significance, with reduced free travel contributing to lower impact velocity, overload, and improved output performance of the pyrotechnic device. This work offers an efficient approach for exploring the coupling effects of multiple physical fields in prediction and protection of pyroshock and provides valuable insights for optimizing the protection performance of thin-walled circular tubes.