Wave Response Analyses of Floating Crane Structure

Abstract

To analyze the dynamic load of lifting load for floating crane moving in waves is one of the important factors for making the operation manual of the floating crane. In addition, it is necessary to consider the strength of floating crane structure since the inertia load caused by the motion of barge in waves is very large. In this study, the dynamic load of lifting load due to the motion of barge in waves is evaluated by means of elastic response analysis on the interaction between the crane structure and the barge hull body. The tank experiment of acrylic fiber model to one hundredth (1/100) for the floating crane with lifting capacity 3600 tons is made to verify the reasonability of the elastic response analysis. On the other hand, the numerical results of movement between the crane as a rigid structure and the one as an elastic structure are compared for the above-mentioned floating crane. It has been found that(1) They have a good agreement if λ/Lthe wave length to the ship length, is 0.5, but the difference between them become large as λ/L is over 1.0.(2) When the crane is simplified as the elastic structure moving in headseas, the dynamic load of lifting load is about 5% of the lifting load in the case with λ/L=1.5 and the wave height =2 m. However, the dynamic load is 13% of the lifting load under the same conditions if the crane is taken as the rigid structure.