Numerical Simulation of Ductile Fracture in Cylindrical Tube Impacted Against a Rigid Surface

Impact of tubes has an extensive application in crashworthiness. Analytical and numerical studies on axial impact of tubes have been carried out mostly at low-to-moderate impact velocities at which only the buckling of tubes is observed. However, experimental observations show that tubes fracture when the impact velocity is high. The objective of this article is to study the fracture of cylindrical tubes impacted against a rigid surface by numerical simulation. First, through-the-thickness fracture at the impacted end is simulated at the impact velocity of 350 m/s. Then, a detailed parametric study is carried out with respect to various parameters like the friction coefficient, tube thickness, tube length, and impact velocity. With an increase in the friction coefficient, the spread of fracture is more toward the outer edge. Further, the spread of fracture toward the inner edge takes place in an inclined manner. At higher tube thickness, the spread of fracture ceases after some time without reaching the inner edge. The tube length is found to have no effect on the fracture. It is observed that the fracture spreads faster with the impact velocity.