Study Of Natural And Forced Vibration Analysis On Very Large Container Vessels

In this paper, the vibration response of very large container ship is studied. Target vessel in this paper chooses10000TEU very large container ship designed by708Institute independently. Meanwhile, the author participates in the vibration calculation and testing of the target ship. In this paper, four main aspects are studied.(1) The calculation and study of hull vibration excitation source.(2) The calculation and study of the natural frequency of the hull and research.(3) The calculation and study of hull vibration response.(4) The calculation and study of local vibration.Firstly, the article describes the principle and calculation methods of the engine and propeller incentive. Using of these methods calculate and estimate vibration excitation of the target ship. Combining with the results, these methods are compared and discussed.Secondly, the article describes several common used method of calculation of natural vibration. Usually, with the stage of design, the calculation of natural vibration is from the experience to detailed calculation. This article uses the FE method to calculate natural frequency of single and double islands’10000TEU container. With calculation results, influence of deckhouse arrangement to ship hull vibration is compared and discussed.According to the calculation of the excitation forces in the second chapter, pulse pressure of propeller is simulated by Matlab, and loaded on hull surface. In order to reflect the influence of main engine, frame vibration and load excitation moments, this paper integrates main engine into the FEM ship hull.Additionally, the article describes the two method of calculation of hull vibration response, the transfer matrix method and finite element method. The vibration response of10000TEU container with single island and double islands are calculated. Combined with the calculation results, the impact of different deckhouse arrangements to hull vibration response is discussed.Finally, this article details two methods of calculating the local vibration, rules by the Det Norske Veritas (DNV) and Germanischer Lloyd (GL). Local vibration in deckhouse and stern structure of10000TEU container is calculated and assessed by two methods. Meanwhile, with calculation results, two methods are compared and discussed.