汽车天窗噪声源介绍和模态分析与优化

Vehicle Sunroof Noise Sources Introduction and Modal Analysis Optimization

介绍汽车天窗噪声源及应对措施,其中发动机和路面等激励是引起天窗结构振动噪声的一个重要噪声源,解决此问题的方法就是使汽车天窗的固有频率与激励频率之间差3 Hz以上。为了在汽车天窗前期开发阶段利用CAE技术准确预测汽车天窗的固有频率,进行了相关性研究,发现汽车天窗是一个高度非线性的系统,即随着基础激励量级的增大,系统固有频率减小,相对阻尼系数增大,同时也发现了在越低能量级激励下扫频测试得出的共振频率和加速度响应与CAE结果差异越小。最后介绍了根据模态应变能结果优化天窗模态的案例。

The vehicle sunroof noise sources and solutions were introduced. It was one of important sunroof structural noise which caused by engine and road excitation. In order to solve the structure resonance problem,the gap between the excited frequency and structural natural frequency should be more than 3 Hz at least. In the early stage of sunroof development,in order to accurately predict sunroof natural frequency with CAE,natural frequency test and CAE analysis based on one sunroof were made. It is found that the sunroof is a highly nonlinear system,the higher the excitation energy,the smaller the sunroof natural frequency,the bigger the relative damping coefficient. And there is good correlation between the CAE results and frequency sweep test based on lower energy exciting. Finally,a sunroof modal optimization case based on modal strain energy results was introduced.