Numerical Analysis of Fracture in Notched Cylinder under Internal Explosive Loading, Using CLE Method

The detonation of explosive materials in a cylindrical shell releases abruptly a large amount of energy that may cause fracture of shell to a number of fragments with various shapes, sizes and masses. There are several methods for controlling fracture such as creating grooves on the surfaces of the cylinder. The depth, direction and cross section of the grooves and the distance between the grooves are important parameters for the fracture control of cylinders. The numerical simulation of fracture can be one of the most appropriate techniques for studying this phenomenon and for reducing the number of complicated, expensive and dangerous experiments that have to be performed. In this paper, the first fracture of a cylindrical shell under explosive loading is simulated numerically using the code LS-DYNA (CLE Method) and then the effects of groove arrangements on the cylinder fragmentation are evaluated. The results show that the longitudinal grooves have the major effect in controlling fracture. However, by choosing appropriate groove depths one may control the fragmentation both in the axial and in the circumferential directions. Moreover, the external grooves are not suitable for controlling the fragmentation.