Study on directional explosion venting characteristics of anti-explosion vessel with shear pin

Once an explosion accident occurs on a civil aviation aircraft, it will cause fatal damage to the aircraft structure. In order to provide a research basis for the structural design and engineering application of airborne anti-explosion vessel, the directional explosion venting characteristics of anti-explosion vessel with shear pin were studied. The structure system is mainly composed of cylindrical vessel, venting cover, shear pin and aluminum alloy panel. Firstly, the numerical model of anti-explosion vessel under implosion was established with LS-DYNA. The critical diameter of shear pin was obtained in the explosion tests and the reliability of the model was verified. Then, the propagation of shock wave and distribution of blast loading in the anti-explosion vessel were elucidated by analyzing the distribution of explosion flow field and changes in shock wave pressure. Meanwhile, the motion law of venting cover during the process of explosion venting was studied by varying the TNT charge mass and shear pin diameter. Finally, a functional relationship between the charge weight and shear pin diameter was established under different venting cover masses, to investigate the critical fracture issue of the shear pin. The results show that the critical diameter of the shear pin is determined to be 22mm through 100g TNT internal explosion tests. Following the TNT explosion, the shock wave propagates reciprocally in the vessel. At approximately 3.8ms, the venting cover is ejected from the vessel, while the residual pressure at the bottom of the vessel is approximately 0.5MPa by 5ms.