Experimental, numerical, and theoretical studies of the response of short cylindrical stainless steel tubes under lateral air blast loading

Abstract

This paper presents a series of experimental, numerical and theoretical analyses of cylindrical tubes subjected to lateral external air blast loading. The cylindrical tubes are laterally loaded in the mid span using cylindrical TNT with a charge mass of 20, 25, 30, and 40 g detonated at a stand-off distance of 50, 100, and 150 mm. The resultant impulses produce failures ranging from large inelastic deformation of the cylindrical tube to tearing of the structure. The results are compared with a modal solution and numerical simulations carried out in ABAQUS 6.12-1, where good correlations with the numerical simulations are observed. The experimentally obtained deformed cross-section can be divided into three parts: a flat top section, two arcs near the flat top and an undeformed circular arc at the bottom. The axial deformation section can also be divided into three parts: the first part is a large plastic deformation region at the center of the structure that divides two outward moving plastic hinges from the second part, which can be defined as a rigid section moving around the plastic hinge at the support, and the third part is the undeformed boundary region. The above deformation patterns were used to develop a theoretical model based on a rigid-plastic analysis. Since the experimental pressure of the cylindrical explosive was more localized than the theoretically defined pressure distribution, the modal solution together with the upper bound yield condition of the tube used in the analysis, overestimated the resistance of the tube.