为解决齿轮箱机脚结构噪声超标问题，利用LMS VituralLab软件从动力学仿真、模态、传递路径和模态贡献度几个方面对该机组进行了振动分析和噪声预估。首先，对齿轮系进行动力学仿真，得到轴承动态力。然后，采用基于模态叠加法的强迫振动响应分析方法，计算得到齿轮箱机脚位置的结构噪声。最后，针对超标现象，对齿轮箱进行传递函数与模态贡献度分析，提出结构优化方案。根据模态振型可锁定振动最敏感位置，并在此处采取增加肋板的方式。优化后的振动仿真结果及声学边界元法计算出辐射声场的声压分布表明：传递函数和模态贡献度有明显改善，齿轮箱机脚振动较优化前减小了3.2 dB，辐射声场的声压级可以满足指标要求。该仿真分析与结构优化方法可有效指导实际工程机组的优化设计。

For the problem of machine foot noise of a gearbox exceeding standard level,the gearbox vibration and noise have been investigated and evaluated using methods of dynamic simulation,modal analysis,TPA analysis and modal contribution degree analysis with the software LMS VituralLab.Firstly,dynamic forces of bearing have been acquired through dynamic simulation for gear transmission.By using the method of forced vibration response,structural noise at machine feet of gearbox is calculated.Then,aiming at the excessive structural noise,mechanical transfer function and modal contribution of gearbox is analyzed,followed by the structural optimization approach.According to the vibration mode,the most sensitive location can be determined and ribs are added.With this optimization,the vibration simulation result and the sound pressure of radiation sound field calculated by acoustic boundary element method indicate that the transfer function and modal contribution have been improved.In addition,the vibration of the mechanical feet has been reduced by 3.2 dB and the sound pressure of the radiation sound filed meets the requirement.The simulation analysis and structure optimization method can be used to guide the optimization of actual engineering unit .

TH132.41

吉林省科技厅十三五重点科技研发项目（20180201001SF）；吉林市科技创新发展项目（201750238）；吉林省教育厅“十三五”科研项目（JJKH20190703KJ）