在铁道车辆的安全运行中,部分路段的轨道扣件系统的折断率比较高,因此掌握轨道扣件弹条的模态参数对减少弹条折断率,提高铁路运营安全性是十分必要的.首先介绍利用基于声振互易法进行模态测试的基本原理,然后利用加速度传感器和声传感器分别对弹条进行测试,得到加速度传感器的附加质量,使弹条各阶固有频率降低3％左右,对于类似扣件弹条这样的小阻尼结构,较小的频率变化会引起较大的频响函数幅值变化,并且通过后续的现场实验对比得到,利用声振互易法对现场弹条的模态测试不会受到钢轨的辐射噪声干扰,可以有效消除接触式传感器附加质量对弹条扣件小阻尼结构模态参数影响,因此得到的实际弹条扣件测试结果更加准确客观.%The broken rate of the rail fastener system in some sections is relatively high in the operation of railway vehicles and it is absolutely necessary to master the modal parameters of the track fastener to reduce the broken rate and improve the safety of railway operation.The basic principle of modal testing based on the method of acoustic vibration reciprocity is introduced first,and then accelerometers and sensors are used to test the elastic strip and obtain the additional mass of the acceleration sensor,which can reduce the natural frequency of the elastic strip by about 3％.And for small damping structures like the fastener,the changes of smaller frequency can cause larger amplitude changes of frequency response function.The subsequent field experiment shows that the modal test of field fasteners could not be disturbed by the radiated noise of the rail,and the influence of the additional mass of the.contact sensor on the modal parameters of the small damping structure of the elastic strip fastener is effectively eliminated.The test results so obtained are more accurate and objective.
展开▼
