Simulation Study of Crack Extension in Concrete Blast Walls Under Blast Impacts

Abstract

To study the crack propagation law of concrete blast wall (CBW) under explosion impact, this paper uses ANSYS/LS-DYNA finite element software to numerically simulate the crack growth law under the influence of different explosion loads and explosion distances. The results show that: after the explosion, the change of composite velocity of each measuring point on the wall at a certain distance from the explosion point is mainly divided into three stages: explosive initiation stage, the composite velocity and acceleration of each measuring point are zero; In the accelerated crack growth stage, the acceleration of each measuring point reaches the peak value; At the stage of uniform crack growth, the crack will no longer accelerate its diffusion. When the explosion distance is fixed, the explosion load is positively correlated with the number of radial cracks; When the explosion load is small, there are only inconspicuous circumferential cracks in the center of the wall. When TNT equivalent is 15g, 25g, and 30g, CBW circumferential cracks increase and mainly concentrate in the center, and gradually expand outward to the boundary in the form of concentric circles. At the same time, when the explosion load is constant, the explosion distance is negatively related to the number of cracks, mainly radial cracks, while circumferential cracks are always distributed in the center of the wall. In the range of simulated explosion distance, the cracks only appear at the boundary and gradually change from square to round with the increase of explosion distance, and the crack area decreases. The research results can provide a theoretical basis for avoiding such accidents and a powerful reference for accident investigators to determine the location and intensity of explosion sources.