Optimal Loading System to Prevent Cargo Damage in Rough Sea Navigation from Viewpoint of Vibration Response

船舶海上运输需要在比公路或铁路运输更复杂的自然条件下运行。特别是船舶在波浪中的运动对于更准确地评估船舶的安全性是非常重要的。虽然在海军建筑领域已经积累了大量的研究和理论，但从船舶在实际海域中由于大的运动而导致货物损坏的角度进行安全评估的实例却很少。本研究以国内20,000吨级客轮为研究对象，设计了全方位观测系统，实现了对船舶运动、货物甲板加速度、车辆货物绑扎力的连续数据库。从这些数据库中可以发现货物碰撞与船舶运动之间的一些关系。此外，这些数据可以在2011年3月11日，当日本东北地区发生前所未有的地震和海啸时观察到。这艘渡轮在离震中很近的宫城县附近。在观测到的垂直加速度中，在10 Hz附近识别出显著的响应。类似的现象在海上的船只上也是如此，在陆地上也是如此。货物甲板加速度与系索力的关系几乎可以用船舶运动和波浪条件来解释。目前，我们正在构建船舶运动对货损影响的动态仿真算法，为海上汽车货运作业的安全管理提供新的思路。

Maritime transportation with vessels is required to operate under more complicated natural conditions than road or rail transportations. Especially, ship motions in waves are very important to evaluate safety more precisely. Although many studies and theories have been accumulated in the field of naval architecture, there are few examples on the safety evaluation from viewpoint of cargo damage due to large ship motions in actual seas. In this study, the total observation system is newly designed to enable continuous database of ship motions, cargo deck accelerations, lashing forces of vehicle cargo in a 20,000DWT class domestic ferry. Some relations can be revealed between cargo impacts and ship motions from these databases. Moreover, these kinds of data can be observed in March 11, 2011, when theunprecedented size of seaquake and tsunami in Tohoku District, Japan. The ferry was off Miyagi Prefecture,which is very near from epicenter of the seaquake. The remarkable response is recognized around 10Hz in observed vertical acceleration. The similar phenomenon is assured in vessels at sea, as well as that in land. Relations of cargo deck accelerations and lashing forces can be almost explained by ship motions and wave conditions in rough seas. Now we are constructing the dynamic simulation algorithm about cargo damage due to ship motions, and it contributes to the new safety management of vehicle cargo operation at seas.