Experimental and Peridynamic Numerical Study on the Opening Process of the Soft PSD in Pulse Solid Rocket Motors

As a critical component of pulse solid rocket motors (SRMs), the soft pulse separation device (PSD) is vital in enabling multi-pulse propulsion and has become a breakthrough in SRM engineering applications. To investigate the opening performance of the PSD, an axial PSD incorporating a star-shaped prefabricated defect was designed. The opening process was simulated using peridynamics, yielding the strain field distribution and the corresponding failure mode. A single-opening verification test was conducted. The simulation results showed good agreement with the experimental data, demonstrating the reliability of the peridynamic modeling approach. Furthermore, the effects of the prefabricated defect shape and depth on the opening performance of the PSD were analyzed through simulation. The research results indicate that the established constitutive model and failure criteria based on peridynamics can reasonably predict the failure location and the opening pressure of the soft PSD. Under the impact loading, the weak zone of the soft PSD firstly ruptures, and the damaged area gradually propagates along with the prefabricated defect, eventually leading to complete separation. A smaller prefabricated defect depth or a wider prefabricated defect distribution can cause a reduction in opening pressure. These research results provide valuable guidance for the preliminary design and optimization of PSDs in pulse solid rocket motors.