الفهرس | Only 14 pages are availabe for public view |
Abstract Improving the ship structure, in terms of crashworthiness, has been the main focus for structural analysts due to the continuous increase in ship collisions which leads to damaging the marine environment, casualties, as well as financial loss. Therefore, improving the ship’s crashworthiness and reaching an enhanced design of the ship is the main concern in this thesis, specifically concerning the influence of high-speed collision and the effects of the high strain rates on the material behavior. Since ship collision analysis involves nonlinear material behavior, the Johnson-Cook model is chosen to investigate the effect of high strain rate. Additionally, a distribution of the local strain rate is analyzed numerically, as well as a relationship between the strain rate and collision velocity, which contradicts previous studies. In addition, a simple case study of a torpedo hitting a stiffened panel without explosion is implemented to examine the effect of strain rate on absorbed energy, and the results questioned the notion of absorbed energy under the stress-strain curve. Finally, an optimization process is established to optimize the side structure of a double-hull tanker hit by a non-exploding torpedo to maximize the ship’s crashworthiness in a high-speed collision. |