SPH-FEM simulation of shaped-charge jet penetration into double hull: a comparison study for steel and SPS

TLDR: In this paper, a hybrid algorithm fully utilizing advantages of both SPH and FEM is proposed to simulate a metal-jet penetration into a double hull made of different materials, namely steel and SPS (Sandwich Plate System).

About: This article is published in Composite Structures.The article was published on 2016-11-01 and is currently open access. It has received 31 citations till now. The article focuses on the topics: Finite element method.

Figures

Fig. 8. Process of penetration of second shell in Case A.

Fig. 7. Process of jet penetration into structures at 180 ls, 240 ls and 400 ls: (a)–(c) Case A; (d)–(f) Cases B.

Table 1 Parameters in Jones-Wilkins-Lee EoS for explosive gas [52].

Table 2 Parameters in Mie-Grüneisen EoS for copper [53].

Fig. 9. Process of penetration of second shell in Case B.

Table 4 Parameters in Cowper-Symonds model for steel and polyurethane [55–57].

Frequently asked questions

Q1. What contributions have the authors mentioned in the paper "Sph-fem simulation of shaped-charge jet penetration into double hull: a comparison study for steel and sps" ?

In this paper, a hybrid algorithm fully utilizing advantages of both SPH and FEM is proposed to simulate a metal-jet penetration into a double hull made of different materials – steel and SPS ( Sandwich Plate System ). First, a SPH-FEM model of a sphere impacting a plate was developed, and its results were compared with experimental data to validate the suggested algorithm. 

Q2. What was the material of the hemispherical liner?

Copper was used as the material of the hemispherical liner, with the magnitudes of outer radius R = 160 mm and thickness d = 8 mm. 

Q3. What is the disadvantage of meshless sph?

computational difficulties can be caused by element distortion when traditional mesh-based methods are used to deal with nonlinear problems of high-speed impact. 

Q4. What was the impact effect of the second shell?

As a result of the impact effect, the shell developed a pit with a greater plastic deformation, and shear failure occurred at the contact point. 

Q5. What is the main purpose of this paper?

In this paper, SPH and FEM are combined to fully utilize their advantages in simulations of the entire process of jet formation and target penetration. 

Q6. What is the purpose of this paper?

In this paper, a hybrid SPH-FEM model was suggested to simulate the entire process of a metal-jet formation and its penetration into a double-hull structure. 

Q7. What was the impact force of the second shell?

As for the second shell, the steel shell in Case A was initially damaged by a spherical fragment, with the bulge sheared off, and the damage zone increased gradually as it was penetrated by other fragments. 

Q8. What is the value of the field function f x?

In the second step – particle approximation – the field function f ðxÞ and its derivative rf ðxÞ are approximated as weighted sum over surrounding particles within the support domain, which can be written as [51] hf ðxiÞi ¼ XN j mj qj f ðxjÞWij; ð2Þq0 (kg/m 3) A (Pa) B (Pa) R1 R2 x e (J/kg)hr f ðxiÞi ¼ XN j¼1 mj qj f ðxjÞ riWij; ð3Þwhere hf ðxiÞi is the approximated value for particle i; N is the number of particles in the support domain; x, m and q denote the coordinates, mass and density, respectively; 

Q9. What was the effect of the jet on the shell?

the jet trended to bend and became thin due to the resistance effect of the composite layer in Case B.Damage characteristics obtained in simulations are discussed in this section after studying evaluation of the jet’s shape during the penetration process. 

Q10. What is the important aspect of the SPH method?

BaêtaNeves and Ferreira [9] successfully applied a two-dimensional SPH formulation using cylindrical coordinates to simulate a jetformation process for a cylindrical-shaped charge (CSC). 

Q11. What was the effect of the jet on the hole’s radius?

8. In particular, the hole’s radius surged in Fig. 8 at about 490 ls due to the accumulation of fragments and the jet’s rebound, which could also be found in this curve. 

Q12. What disadvantages do steels have in terms of density?

Although steels have been widely used as armour materials in defence applications, they have a disadvantage of a relatively high density.