基于复合建模方法的轴系扭转振动特性及仿真

发布时间：2018-06-15 19:44

本文选题：轴系扭转振动 + 连续离散复合系统　；参考：《船舶工程》2016年06期

【摘要】：为了提高主机轴系计算准确度,提出了一种新型的主机轴系建模方法。该方法将主机轴系分为连续子系统和离散子系统,推进轴段如螺旋桨轴、中间轴、螺旋桨及法兰划分为连续子系统,柴油机曲轴端划分为离散子系统。分别应用波分析法和多自由度动力特性分析,得到连续子系统和离散子系统的控制方程,同时通过边界条件将两个子系统动态刚度矩阵连接,推导出全局控制方程。对某型主机轴系扭转振动计算进行了仿真分析,并与传统建模方法比较。从计算结果可知,在高阶模态上,新型建模方法计算更精确,更接近真实振动状态,同时在保证相同计算精度的情况下,新型建模计算方法计算时间和计算资源占用较少,相对更为简便。同时,新型建模方法克服了当模态节点集中于轴段时,传统建模方法由于将轴系等效为一至两个质量单元而引起的节点偏移所带来的误差,这在实际主机轴系计算特别是长推进轴和刚度较低的轴系计算中具有重要意义。
[Abstract]:In order to improve the calculation accuracy of host shafting, a new modeling method for mainframe shafting is proposed. In this method, the shaft system of the main engine is divided into continuous subsystem and discrete subsystem. The propeller shaft such as propeller shaft, intermediate shaft, propeller and flange is divided into continuous subsystem, and the crankshaft end of diesel engine is divided into discrete subsystem. The control equations of the continuous subsystem and the discrete subsystem are obtained by using the wave analysis method and the dynamic characteristic analysis of the multi-degree-of-freedom respectively. The dynamic stiffness matrix of the two subsystems is connected by boundary conditions and the global control equation is derived. The torsional vibration calculation of a main engine shafting is simulated and analyzed, and compared with the traditional modeling method. The calculation results show that the new modeling method is more accurate and closer to the real vibration state in higher-order modes. At the same time, under the condition of the same calculation precision, the new modeling method takes less computation time and computing resources. Relatively simple. At the same time, the new modeling method overcomes the errors caused by the node offset caused by the shafting being equivalent to one or two mass units when the modal nodes are concentrated on the shaft segment. This is of great significance in the calculation of actual mainframe shafting, especially in the calculation of long propeller shafts and shafting with low stiffness.
【作者单位】：上海机电工程研究所;上海交通大学海洋工程国家重点实验室;
【分类号】：U664.21

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