Title: Dynamic fracture characteristics of cylindrical steel shell under internal blast loading

Authors: Yongle Hu; Qicheng Liu; Shuxin Bai; Hong Zhang

Addresses: Key Laboratory of Safety Design and Reliability Technology for Engineering Vehicle, Changsha University of Science and Technology, Hunan Province, Changsha 410004, China ' College of Physics and Electronic Science, Changsha University of Science and Technology, Changsha 410004, China ' College of Aerospace and Material Engineering, National University of Defense Technology, Changsha 300072, China ' College of Aerospace and Material Engineering, National University of Defense Technology, Changsha 300072, China

Abstract: Dynamic fracture characteristics are the foundation for conducting safety assessment and failure analysis of explosion containment vessels (ECVs) subjected to internal blast loading. The experiment was conducted to investigate dynamic fracture characteristics of cylindrical steel shells subjected to internal blast loading at the centre. The elastic-plastic response of cylindrical steel shells was simulated numerically by using nonlinear dynamic finite element analysis code LS-DYNA. The fracture mode and mechanism of a cylindrical shell were specially studied by means of the analysis of deformation, macrographs and meso-graphs of fracture surface and elastic-plastic response. The results show that the axial direction fracture surface of the cylindrical steel shell exhibits a mixed ductile fracture mode with shearing dimple by micro-voids coalescence. Dynamical ductility deformations appear and the shear bands form when the cylindrical steel shell expands under internal blast loading. The fracture mechanism is that the shear bands destroyed the initiation and growth of the micro-voids and micro-cracks along the shear bands due to its softening effect under tensile circumferential stress. The shear bands and the tensile circumferential stress dominate the final fracture mode. The fracture mode is the ductile fracture.

Keywords: cylindrical steel shells; plastic deformation; shearing bands; shearing dimple fracture mode; dynamic fracture; internal blast loading; safety assessment; failure analysis; explosion containment vessels; ECVs; simulation; nonlinear FEA; finite element analysis; elastic-plastic response; ductile fracture; crack initiation; crack growth; micro-voids; micro-cracks; tensile stress.

DOI: 10.1504/IJMSI.2014.067116

International Journal of Materials and Structural Integrity, 2014 Vol.8 No.4, pp.291 - 302

Published online: 31 Jan 2015 *

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