Numerical Simulation Study of Expanding Fracture of 45 Steel Cylindrical Shell under Different Detonation Pressure

Abstract

Detonation and fragmentation of ductile cylindrical metal shells is a complicated physical phenomenon of material and structural fracture under a high strain rate and high-speed impact. In this article, the smoothed particle hydrodynamics (SPH) numerical model is adopted to study this problem. The model′s reliability is initially tested by comparing the simulation findings with experimental data, and it shows that different fracture modes of cylindrical shells can be obtained by using the same model with a unified constitutive model and failure parameters. By using this model to analyze the explosive fracture process of the cylindrical shells at various detonation pressures, it shows that when the detonation pressure decreases, the cylindrical metal shell fracture changes from a pure shear to tensile–shear mixed fracture. When the detonation pressure is above 31 GPA, a pure shear fracture appears in the shell during the loading stage of shell expansion, and the crack has an angle of 45° or 135° from the radial direction. When the pressure is reduced to 23 GPA, the fracture mode changes to tension–shear mixing, and the proportion of tensile cracks is about one-sixth of the shell fracture. With the explosion pressure reduced to 13 GPA, the proportion of tensile cracks is increased to about one-half of the shell fracture. Finally, the failure mechanism of the different fracture modes was analyzed under different detonation pressures by studying the stress and strain curves in the shells.

Study on cutting performance of aramid fiber weaving material by linear shaped charge

“…   (7) Where, vp  is von Mises flow stress; vp  is viscoplastic strain; A is yield strength; B is the plastic hardening coefficient of the material; C is viscoplastic hardening index; n is the strain rate sensitivity index; ' vp  is the true viscoplastic strain rate; ' 0  is the reference strain rate; m is the temperature softening index; T* is the dimensionless temperature, and the following formula is the T* calculation formula:…”

“…The existing research [4][5][6] mainly focuses on the cutting ability and influencing factors of different metal materials and composite materials by different types of linear shaped charge. At the same time, because the linear shaped charge rely on the explosive energy, the damage form of external structures and protective structures is also a key research issue [7][8][9].…”

Identification of the pulse axisymmetric load acting on a composite cylindrical shell, inhomogeneous in length, made of different materials

“…Separately, it is worth highlighting those works that are related to the destruction of cylindrical shells. For example, paper [20] considers their detonation and fragmentation under conditions of high deformation rate and high-speed impact. The cited paper uses a numerical model of fluid dynamics of smoothed particles (SPH) to study this problem.…”

“…The following conclusions can be drawn from the above literature review [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]:…”

“…-most papers [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] contain solutions only to direct problems that are solved by numerical methods, often by special software systems based on FEM, for example, LS-DYNA;…”