约束和长度对管道共振的影响

Impact of Constraints and Length on Pipeline Resonance

共振对管道危害极大,为了防止共振,需要对管道的固有频率和振幅进行研究。管道的约束和长度是影响管道固有频率和振幅的2个重要因素,变换管道约束和长度能有效改变管道固有频率和振幅的大小。采用ANSYS软件建立管道的有限元模型并对其进行模态分析,得到前三阶固有频率和振幅。通过改变管道约束和长度,得出管道振动规律:约束不同时管道的固有频率差别很大;其他条件相同时,管道固有频率随着管道长度的增加而减小;约束方式对振幅的大小有影响,一端固定时振幅最大;其他条件相同时,振幅的大小随着长度的增加而减小。

In order to prevent resonance which has great harm to the pipeline, it is necessary to study the natural frequency and the amplitude of the pipes. The constraints and the length of pipeline are the two important factors affecting natural frequen- cies and amplitude of pipeline. The changes of constraints and length of pipeline can effectively influence pipeline＇s natural fre- quencies. ANSYS software was adopted to establish the finite element model of pipeline then the first three natural frequencies and amplitude were obtained by analyzing the model. By changing the pipe constraints and length of the pipeline, the vibration rules were found ： different constraints on pipeline will lead to big difference on natural frequencies of pipeline and pipeline natu- ral frequency decreases with the increase of pipe length when other things are equal ; constraints will also influence the size of the amplitude, the amplitude value is largest when the pipeline is fixed at one end; and the magnitude of the amplitude decreases with increasing length when other conditions are the same.