Study on the Vibration of Bulk Carrier

对散货船顶部侧舱的剧烈振动进行了测量，已有几篇报道。为了研究这些振动，将船舶分为主舱、底部舱和顶部舱，并计算了这些结构之间的耦合振动。在该方法中，主船体、底部和顶部侧舱分别表示为timoshenko梁、正交各向异性板和弯扭梁。通过与实验结果的比较，验证了该计算方法的准确性。但没有对实际船舶的剧烈振动进行计算。因此，认为顶侧罐的造型不合适。在此基础上，提出了一种考虑截面变形的薄壁弹性梁的振动计算方法。考虑顶舱截面的变形影响，计算了实际船舶的振动，得到了以顶舱为主的自振。

There are several report in which the Violent vibration was measured at the top side tank of bulk carrier. In order to investigate these vibration, the ship was divided into the main bull, bottom and top side tank, and the coupled vibration among these structures was calculated. In this method, the main hull, bottom and top side tank were expressed as the Timoshenko-beam, orthotropic plate and bending-torsional beam respectively. The accuracy of this calculation method was confirmed by the comparison between the calculated and the experimental results. But the violent vibration which was seen on actual ship was not calculated.For this reason, it was considered that the modeling of top side tank is not proper. Then, a method to calculate the vibration of the thin walled elastic beam like the top side tank was proposed, in which the deformation of cross section was considered. The vibration of actual ship was calculated considering deformation effect of cross section of top side tank, and the natural vibration at which the vibration of top side tank becom dominant was obtained.