Towards Numerical Simulation and Model Test Verifications for an Analytical Model of Tubular Member Under Lateral Impact Scenario

Abstract

Tubular member of jacket platform has the possibility of being struck by the service ship under a lateral impact scenario. An analytical theoretical method has been proposed to predict the structural deformation and the resistance force. This paper addresses a study on the verifications for this analytical method, through numerical simulation and model test methods. The analytical method was proposed based on a new structural sectional deformation mode, which considers both of the local denting and global bending deformation. The analytical method is briefly introduced. The verification work includes three steps. Firstly, a model test was conducted, on purpose of obtaining the structural deformation and the resistance force under the lateral impact scenario when a model tubular member was struck by a wedge hammer. In the test, the tubular member was fixed at both ends and the wedge hammer hit at its middle position. A high speed camera was used to record the instantaneous motion track of the hammer, and with the motion track data, the striking force and the indentation can be obtained. Then, a curve of impact force vs. indentation in time series was got. Secondly, the numerical simulations were conducted to simulate the corresponding impact scenario. The code LS_DYNA was used. The curve of impact force vs. indentation was also obtained. Finally, a comparison study was made, to verify the accuracy of the analytical theoretical model, and it is proved that the curves match well. Furthermore, four more cases were conducted by numerical simulations, to assess the feasibility of the analytical method on prototype scantling using for the tubular member of jacket platform.