Research On Deformation Mechanisms Of Ship Hull Plate In Grounding And Collision Scenarios

Grounding and collision accidents may occur due to human operational errors or severe environmental conditions during the navigation processes. When a ship runs aground over a narrow pinnacle-shaped rock, the bottom plate is likely to be torn open. Meanwhile, the side shell is also at the risk of being crashed by a bulb-bowed ship. The tearing of ship bottom plate or the crash of the side shell is very dangerous and may result in severe casualties and great economic loss, and, what is worse, causes environmental disasters like crude oil leakage. Carrying out research on ship grounding and collision is conductive to assessing the crashworthiness of a ship during its structural design phase. And it’s also useful to conduct rapid risk assessment for dangerous grounding and collision scenarios. Generally, the methods, which are available for grounding and collision problems can be classified into the following four categories: empirical method, experimental method, nonlinear finite element method and simplified analytical method. Among all the methods, the simplified analytical method can provide clear insight into the structural deformation mechanism and good predicting accuracy can be obtained with only a small amount of calculation. Therefore, this method is widely applied in ship grounding and collision research.In this paper, the deformation mechanism of ship hull plate in dangerous grounding and collision scenarios is studied specifically. The work mainly composed of two parts. The scenarios, that a ship running aground over a narrow pinnacle-shaped rock and the side shell being crashed by a bulb-bowed ship, are considered. In the first part of the main work, a theoretical model for ship bottom plate tearing when the ship runs grounding over a cone-shaped rock is proposed. And the analytical solution of the plate tearing force can be calculated. Another part focuses on a rectangular shell plate indented by a spheroidicity collision head. The relationship of the collision force and penetration depth can be obtained with the newly proposed theoretical method. Two sets of verification work, which means verifications through former related experiments and through numerical simulations, have been done to validate the newly proposed models and good agreements have been obtained.Results and conclusions in this paper may benefit the assessment of s ship’s crashworthiness during its structural design phase and rapid risk assessment for dangerous grounding and collision scenarios.