Bioinspired Microgroove’s Geometry Design and Finite Element Analysis of Bursting Influence Parameters for Metal-based Rupture Diaphragms

Abstract

Serving as the initiating explosive devices between the propellant tank and the engines, metal-based rupture diaphragms are widely used in ramjet igniters owing to the advantages provided by their simple structure, small size, and low cost. However, the reliability of rupture pressure directly affects the success of engine ignition and rocket launch, which is mainly influenced by factors like material, structure, and residual thickness of the surface notch of the diaphragm. Among those, the geometry of the notch is easy to define and control when compared to the mechanical parameters of the ruptured diaphragm. Thus, to make the diaphragm rupture (1A30 Al) within the required pressure range (0.4 MPa ± 3.5%) with highly sensitive and reliability, we draw inspiration from the arthropod’s force-sensitive slit organ which encompasses curved microgrooves to design a Ω-shaped notch for the rupture diaphragm. Finite element analysis is used to study the relationship between the burst pressure and geometric dimension of the Ω-shaped and bioinspired microgroove. Based on that, metal-based rupture diaphragms are fabricated by femtosecond laser processing technology, followed by rupture tests. Experiment results demonstrate that the practical rupture pressure of the diaphragm is highly consistent with the finite element analysis results, which verifies the effectiveness of the bionic design.