Simulation of the Deformation and Failure Characteristics of a Cylinder Shell under Internal Explosion

Abstract

Under the load of an internal explosion shock wave, the failure of a cylindrical shell is the basis of safety evaluation and failure analysis of explosion vessel design. This paper carried out the explosion loading experiment of a cylindrical shell, and used the nonlinear dynamic finite element analysis program LS-DYNA for the dynamic response of the cylindrical shell along the directions of thickness and length, and analyzed the failure law of a cylindrical shell. The results showed that the deformation of the core section of the cylindrical shell was not different in the same specific distance, the strain decreased more slowly with the increase of thickness at the end of the explosion center, and the expansion failure process and fracture mode of metal shell under explosive load were affected by the material and structure size of the shell, as well as the characteristics and mode of the load. Based on the plastic theory, this paper discussed the evolution characteristics of the stress state during the expansion process of cylindrical shells under different explosion pressures, and analyzed the explosion pressure effect on the tensile fracture and shear fracture. The expansion failure experiment of a 20# steel-made cylindrical shell and the microscopic and metallographic analysis of the recovered debris were carried out.

Prediction of Peak Overpressure of Charge Enveloped by Polymer Matrix Composite: Theoretical Modeling and Experimental Verification

“…where K a and ρ a are the isentropic index and density of undisturbed air, respectively. Finally, the initial parameters of the explosion shock wave can be determined by combining Equations ( 2) and (10). The calculation results obtained from several α m values are presented in Table 1.…”

“…To determine the value of overpressure, the initial outflow position of the shock wave was determined by Equations ( 1) and ( 2), and the initial pressure, px, was calculated using Equation (10). Combined with the initial pressure, outflow position, and Equation ( 12), the equivalent charge mass was calculated and the overpressure at different propagation distances was obtained.…”

“…The introduction of non-detonating materials may result in the explosive reaction mechanism of the charge being significantly different from the energy output structure. On the one hand, the polymer matrix composite shell will undergo large deformation and dissipate energy in the early stages of the explosion, unlike traditional metal cylindrical shells [ 10 , 11 ]; on the other hand, the shell may disperse with the detonation products, which obviously affects the generation of a blast shock wave [ 12 ]. Considering the complexity of the dynamic mechanical properties and explosion response of non-detonation materials, many studies have investigated the explosive power of inert shell charges [ 13 , 14 , 15 ].…”

An Innovative Failure Criterion for Metal Cylindrical Shells under Explosive Loads

“…The results of the finite element analysis are listed in Table 1. According to the literature [21,36], LS-DYNA is used to simulate the dynamic failure of metal cylindrical shells. During the explosion, the impact load on the inner wall can generate several periodic pulses.…”

Design and failure analysis of cylindrical shells due to explosive loads

“…To resist the explosive, proper design characteristics are required. [1] The design of the cylindrical shell involves determining the appropriate dimensions, material and the thickness of the shell required to withstand the loads and stresses. The loads and stresses that a cylindrical shell may experience include internal pressure, external pressure, bending, torsion and thermal expansion and contraction.…”