Experimental Investigation on the Deformation and Fracture of Steel Square Tubes under Double-Explosion Loadings

Abstract

The experimental investigations on the square tubes with various stand-off distances and wall thickness were helpful to understand the dynamic response of metal shell under single and double explosion. Therefore, the effect of stand-off distance, wall thickness, and amounts of explosion on the deformation and damage of the square tubes and the regular pattern of the fracture development was analyzed by dimensions of local plastic deformation, volume of the depression area, and crack type. The result reveals that the deformation and fracture mode of steel square tubes gradually transform from local deformation to rupture with the decrease of wall thickness and stand-off distance. Besides, the failure degrees of square tubes under a double explosion were relatively higher than those of square tubes under a single explosion. In addition, the experiment indicates that the side corners of the square tube are very vulnerable, and they are damaged easily by the stress concentration and shear effect. The conclusion provides an important scientific basis for the structural design of square-tube structures and calculation of engineering protection.