Vibration Analysis Of46M Crew Boat

As a complex elastomer, the total vibration condition of the ship belongs to the vibration of the infinite-freedom-degree system, with an infinite number of the degrees of freedom. The free vibration can be decomposed into an unlimited number of vibrations. If the external incentive exists for some reason, it will be likely to cause the resonance of the ship. At the same time, it will lead to the formation of the vibration in different forms. The vibration will cause bad effect on the efficiency of the crew and the health of the passengers. It will also result in the alternating stress of the hull structural components, leading to the fatigue failure and reducing the hull strength. And it will even result in the failure or damage of the equipment and instrumentation, affecting the normal operation of the ship. Therefore, in the ship design stage the natural frequency of vibration of the hull structure must be accurately estimated, which can help to correctly choose the type of the propeller as well as the main engine, to avoid the overall resonance of the ship.The method of finite element analysis has become the popular numerical method in the field of hull structural analysis. ANSYS has been widely used as a large finite element analysis software in the field of hull structural analysis. In this paper, the main task is to complete the analysis of the total vibration characteristics of an aluminum alloy marine working boat. Using ANSYS finite element analysis software and the indirect bottom-up modeling techniques, this paper completes the simulation and analysis of three-dimensional finite element model which is based on the structure of the whole ship. And this paper calculates the quality of the additional water with the Lewis method. When the ANSYS analysis results are gained, this paper will compare the ANSYS results with other results calculated by the empirical formula, and then find out the reasons for the differences.In the process of the modeling of the hull plate, this article explores the modeling method of the complex surface of the hull plate, through the efficient use of the computer. In the ANSYS software, we use the Boolean operations to create the surface of the hull plate. The results prove that this method can improve the speed of modeling, and reduce the workload of the engineering staff. Therefore it is feasible in engineering practice.