Erosion Criteria for Frictional Materials Under Blast Load

Abstract

Detonation is a type of reaction of the explosive that produces shock waves of great intensity. If the explosive is in contact near a solid material, the arrival of the explosive wave to the surface of the explosive generates intensive pressure waves that can produce the crushing or the disintegration of the material. This shock effect is known as brisance effect. If the explosive is surrounded by air, a pressure wave that can fracture masonry and concrete structures is generated.
Both brisance effect and fracture produce discontinuities in the material.
In order to reproduce this type of effects with hydrocodes, an erosion model can be used to remove from the calculus the cells that have reached certain criteria based on deformations. This erosion model represents a numerical remedial to great distortion of Lagrange meshes that can cause excessive deformation of the mesh. For this reason, its application to the simulation of a physical phenomenon requires the calibration with experimental results.
On the other side, erosion criterion and erosion limit used in Lagrange simulations have been found to be important points to study because not only the dimensions of the rupture zone but also the stability of the numerical solution strongly depends on them. A review of different erosion criteria and erosion limits used by different authors to simulate concrete under blast loads is presented in this paper. An application example is developed to show the effect of erosion limit on damage results and the dependence on mesh size. Comparison with experimental results of concrete elements subjected to blast loads is also included in the paper.