中文摘要：

为改善立体编织机运行中产生噪声的问题,建立了立体编织机机头的三维模型,用ANSYS Workbench对其进行了模态分析,得到各阶固有频率和模态振型。在此基础上,设计了编织机的3种运行工况,合理避开了机头的固有频率。同时,在Adams软件中建立了齿轮啮合的多体动力学模型,获得不同工况下齿轮传动的啮合冲击力和轴承的支反力。最后,在LMS Virtual Lab软件中导入模态分析结果文件,建立机头的声振耦合模型;利用窗口函数的傅里叶变换算法,将时域上的轴承支反力转化到频域,作为模型的激励力;通过声振耦合模型,获得并分析了不同负载和转速下的外声场噪声分布,验证了设计的运行工况,解决了正常工况下立体编织机运行时噪声过大的问题,为立体编织机振动噪声的研究提供了理论模型和分析方法。

英文摘要：

To study the noise produced in the 3-D braiding process of 3-D circular braiding machine, a 3-D model of its head section was established. By importing this model into ANSYS Workbench, the modal analysis was carried out and the natural frequencies of the head section were obtained, as well as the modal vibration modes. According to the principle of avoiding natural frequencies, the working conditions were determined. With the multi-body dynamics model of gear transmission set up by Adams, the time-varying force data of both gear mesh and bearing reaction were acquired. And then, the time- varying forces data were converted into frequency domain data by FFT method, which was used as the exciting forces in the model built by LMS Virtual Lab. Combining the modal analysis data with the frequency domain data of bearing reaction forces, the vibro-acoustic coupling model was investigated. Finally, the noise fields under different loads and speeds were obtained, verifying that the designed working conditions could meet the requirements, and the results could provide a reference for the vibro- acoustic research of braiding machine and the field management of practical engineering.