钛合金薄壁空心结构阻尼特性研究

Research on Damping Characteristics of Titanium Alloy Thin Wall Hollow Structure

研究了测试参数对常用阻尼特性测试方法测试结果的影响规律,分析表明自由衰减法测试数据分散性小,半功率带宽法测试数据分散性大并且受测试参数选取影响较大。基于优化后的测试参数对比分析了钛合金薄壁空心、实心结构阻尼特性,研究发现振幅较小时两类结构阻尼特性接近,一阶振型下的模态阻尼在2×10-4量级,高振幅条件下空心结构阻尼比较大,振幅为10mm时阻尼为3.577×10-3,是振幅为3.0mm时阻尼的1.20倍,表明空心结构内部结构特征在大变形条件下可以提供额外阻尼,合理利用这一特征对提高结构性能具有重要意义。

The influence of test parameters on the test results of the commonly used damping characteristics test method was studied. The analysis show that the test data dispersion of the free vibration method is small and the test data dispersion of the half-power bandwidth method is large and greatly affected by the selection of test parameters. The damping characteristics of hollow and solid structures were compared and analyzed based on the optimized test parameters. It is found that the damping characteristics of the two types of structures are similar when the amplitude is small, and the modal damping under the first mode is about 2x 10 3. Under the condition of high amplitude, damping radio of the solid structure increases slightly. When the amplitude is 10mm, the damping is 3.577 x 10 3, which is as many as 1.20 times that of the amplitude being 3.0 mm. It indicates that the internal structural features of the structure can provide additional damping under large deformation conditions. The rational use of this feature is of great significance to improve the structural performance.