考虑船舶轴系校中与弯曲振动的轴承优化布置

船舶在航行过程中，螺旋桨所受到的激振力通过船舶轴系传递给船体并引起尾部振动和噪声，给船舶的乘坐舒适性和安全性带来危害。本文利用传递矩阵法分别建立船舶轴系校中数学模型和弯曲振动数学模型，并使用拟定常法得到螺旋桨叶频和二倍叶频的激励力幅值比值，成比例输入到轴系系统当中，设置轴承间距和轴承标高为变量，以尾轴后轴承受力幅值最小为目标函数。在满足船舶轴系校中标准下，对轴承位置的轴向和径向进行双向优化，得到实例的最优布置方案，通过比较优化前后的尾轴后轴承受力响应幅值，可以发现优化效果明显，对船舶轴系设计与布置具有一定的指导意义。

Optimization of ship shaft bearings location considering shaft alignment and lateral vibration

The exciting force from propeller always transmits through the ship shaft to ship body, and induce vibration of ship stern and noise, causing damage for the ride comfort and safety. In order to solve this problem, shaft alignment and lateral vibration of a shaft are modeled by the transfer matrix method respectively. Quasi-steady empirical method is used for getting the ratio between exciting force of propeller blade frequency and double blade frequency, and then put them into the model according to the ratio. Set the bearing distance and bearing elevation as variables, and minimum force of the propeller shaft rear bearing as objective function, obtaining the optimal solution for bearings location of this shaft under the requirement of shaft alignment. The result shows a good effect after optimization when comparing the response amplitude of rear bearing force. It provides a guide for ship shaft design and bearing arrangement optimization.