大型复杂齿轮箱底架模态分析方法

本文探讨针对某复杂齿轮箱底架结构的一种模态分析方法。该齿轮箱底架尺寸较大,质量与刚度分布情况复杂。试验模态分析所需的试验条件要求高,对于力锤的选择和传感器的数量都有较高的要求。此外在有限元模态分析中会存在模态密集、模态向量繁杂、模态振型云图无法提取等问题。该齿轮箱底架结构特殊,近似案例很少,因而鲜有相关的计算参考。本文主要提出以扫频分析为理论基础,辅以虚拟梁的一种近似方法来求出该复杂大型结构的固有频率与振型。其计算结果较直接模态分析更能体现结构在工作状态下的模态情况,亦能对设备工作频率的选取以及结构刚度优化提供有益的帮助。

Research on modal analysis method of a large complicated gearbox basement

A modal analysis method on a complicated gearbox basement is discussed,which is very large while the distribution of mass and rigidity is ambiguous.The request of operational modal analysis is strict,while there are problems such as intensive modes,multifarious modal vector and invisible total modal shapes in finite element modal analysis.Meanwhile,due to distinctiveness of the basement,there are rarely reference and related cases.Therefore,an estimation based on sweep frequency theory with a skill named as fake beam to acquire the natural frequency and response shape was proposed.The results can show more details of structure modal in work case,and provide a beneficial reference to adjust the working frequency and structure optimization.