The influence of dynamic loads on the FE model of the ship equipment-base system

In ship dynamic response analysis, it is through the equipment base that the dynamic load of ship equipment passes onto the deck, which is called “equipment-base system”. Generally, since it is usually difficult to measure the equipment exciting force yet much easier in measuring the acceleration passed onto the base panel, the research about relevant model-building and the ship dynamic response equivalence of applying these two kinds of loads is of high application value for real projects. Firstly, based on theoretical derivation, the influence of these two kinds of dynamic loads on modelling is analyzed in the particle vibration system. Then, two FE models of a specific hull of an actual ship is established to confirm the validity of the conclusion by comparing the acceleration level of the check points in these two FE models, where one of which is an equipment-base model loaded with exciting force and the other is a single base model loaded with acceleration. The result shows that in the low frequency domain, when the type of dynamic load on the “equipment-base system” is acceleration, it is unnecessary to incorporate equipment or consider its mass in the FE model.