A STUDY ON SHIP VIBRATION USING FINITE ELEMENT METHOD

when the beam theory was used to calculate ship hull vibration,greater discrepancies were found between theoretical cal-culations and actual measurements especially at higher modes.Thusthe beam model cannot be considered as a practical one for higher-mode calculations.This paper presents the application of two-dimensional finite element model for the calculation of ship ver-tical vibration.Using the multi-element structural dynamic a-nalysis program DDJ(DL)developed by ourselves,the hull vibra-tion analysis of two ships(vessel A and vessel B)was carriedout on the Model-709 Computer made in the People’s Republic ofChina.The results of the calculation,when compared with actualmeasurements.show that the two-dimensional model is much moreefficient than the traditional beam model.The agreement be-tween the calculations and measurements has been improved greatly,and this discrepancy at the4th·and5th-modes has decreased towithin5%as compared to that of more than20%in the traditionalmodel.Furthermore.the mode

A study on ship vibration using finite element method

When the beam theory was used to calculate ship hull vibration,greater discrepancies were found between theoretical calculations and actual measurements especially at higher modes.Thus the beam model cannot be considered as a practical one for higher-mode calculations. This paper presents the application of two-dimensional finite element model for the calculation of ship vertical vibration. Using the multi-element structural dynamic a-nalysis program DDJ(DL) developed by ourselves,the hull vibration analysis of two ships (vessel A and vessel B) was carried out on the Model-709 Computer made in the People's Republic of China.The results of the calculation,when compared with actual measurements,show that the two-dimensional model is much more efficient than the traditional beam model. The agreement between the calculations and measurements has been improved greatly,and this discrepancy at the 4th- and 5th~modes has decreased to within 5% as compared to that of more than 20% in the traditional model. Furthermore,the model is relatively simple,the coat and time required for the computation is comparatively lower and shorter,and the calculation can be carried out on a medium-siezed computer. Therefore,this model is especially appropriate for analyzing the dynamic characteristics of ships at early design stages.