管壁不连续对管路中传播的弯曲波的隔离

采用梁弯曲振动的运动方程来求解管壁中传播的弯曲波,然后用传递矩阵的方法得出了弯曲波在通过管壁不连续段后的透射系数矩阵。利用边界条件,分析了管壁材料不连续段及其在管路中的布置情况对弯曲波透射系数的影响,并得出了如下结论:作为管路不连续段的铜管、铝管和挠性胶管都可以对管路中传播的弯曲波起到隔离作用,但它们也都有可能使振动放大。这与频率、边界条件和管路不连续段的布置密切相关;对极低频弯曲波的隔离是十分困难的,甚至是不可能的;管路不连续段的布置情况、管路边界条件(即支撑情况)和频率应当是管路隔振设计中需要特别注意的因素;挠性胶管在可以起隔离作用的条件下能够取得比铜管和铝管更低的透射系数和更大的位移补偿。

Pipe wall discontinuity's isolating the bending wave passing through the pipe

The beam model is used to solve the bending wave passing through the pipe wall and the transmission coefficients matrix when passing through the wall discontinuity is obtained by using the transfer matrix method,based on which,the boundary conditions are introduced to study the influence of the wall's discontinuity and frequency on the transmission coefficient of the bending wave when passing through the wall discontinuity.Finally,the conclusions are obtained as follows: the copper pipe,the aluminium pipe and the flexible rubber pipe all can isolate the bending wave passing through the pipe wall,but it is possible for them to make the vibration worse.It is connected with the frequency,the boundary conditions and the setting of the discontinuity pipe in the pipe systems.It is very hard,or rather impossible,to isolate the bending wave with very low frequencies.Good effects of the isolation depend on the frequency,the boundary conditions and the setting of the discontinuity pipe in the pipe systems.They should be the first to be considered in designing the pipe systems.The use of the flexible rubber pipe can get better isolation effects at the same conditions than the other two,and the flexible rubber pipe can offer necessary displacement compensation but the rigid pipe can not.