A coupled simulation of an explosion inside a lined cavity surrounded by a plastic compressible medium

Abstract

SUMMARYThe paper develops a coupled approach to simulate an axisymmetric explosion inside a buried lined cavity. The approach allows accounting for all the stages of the process: detonation of the internal charge; the shock wave propagation in the internal gas with further interaction with the lining, including multiple reflections; soil-structure dynamic interaction, including multiple gap openings and closures and wave propagation in the surrounding compressible plastic medium.The interaction problem is solved by a combination of the variational difference method and of the modified Godunov's method based on the fixed Eulerian mesh with the so-called mixed cell. The contact pressures acting on the lining due to both detonation products and soil-lining interaction are computed through the solution of the joint system of finite difference equations of gas, shell and soil dynamics using a simple iteration method.

Explosion‐induced dynamic soil–structure interaction analysis with the coupled Godunov–variational difference approach

“…z i j values (26) from the previous time step (the bottom bases of the corresponding STCs) serve as the initial conditions for this problem. These flux values, Z k , allow the calculation of the flux vectors N l (18), W l (19) and H l (20) at the lateral STC faces (l = 1, 2, 3, 4). The vectors N i−1/2, j−1/2 (18) at the bottom base of the STC are known from the previous time step.…”

“…Both the method and the equations have been described in detail in recently published papers [17,18] and therefore only its principles will be presented in this section. The lining is modeled as a thin-wall, elastic-plastic Timoshenko shell [35].…”

“…where is the volumetric strain and i j are the corrections for rotation (see [31]); = 0 and the finite-difference forms of all other i j for the Lagrange approach are presented in [18].…”

“…where is a scalar parameter, which during unloading equals zero and during active loading takes the following form in terms of the work, W [18]:…”

Blast response of a lined cavity in a porous saturated soil

“…Analytical solutions were proposed for relatively simple bilinear soil compaction models excluding shear effects [36][37][38][39]. For more complex soil constitutive equations, various numerical methods are utilized [17,28,30,35,40,41] among which is the Godunov method [42,43].…”