Vibration Research Of Marine Conveying Fluid Pipeline System

The pipeline is the important constituent of marine power unit. The pipeline vibration is the important aspect of the power unit vibration. The intense pipeline vibration can make the appurtenance that installed between the pipeline, specially each kind of welded joint and pipeline support undergo repeatedly alternation vibratory stress, cause the pipeline to withstand the attached fatigue load, urge the fatigue cracking formation and the expansion and become loose,leak even explosion accident. More and more different caliber pipelines are arranged in the ships deck and warehouse room, because of fluid's pulsation and vibration of deck, fluid pulsation causes the pipeline vibration, the pipeline vibration can reduce the pipeline conveying efficiency,cause the structure vibration fatigue,even cause the pipe structure destruction, result in significant economic loss. Not only the ships pipeline system but also the industry pipeline system, the pipeline vibration reducing is very important. The purpose of this paper is to analyze natural vibration property and vibration response of the pipeline system, lower vibration to the lowest level in the course of design and installation of the pipeline, reduce accidents caused by pipeline vibration.The main research contents of this paper are as follows:1 .The geometry model of pipeline is established by three-dimensional model software SolidWorks, and the finite element model of pipeline is established by finite element software MSC. Patran. The finite element model is imported in the MSC. Nastran solver to solve, and computational modal frequencies and mode shapes of pipeline are obtained.2.The pipeline system is analyzed with experimental modal method, experimental modal frequencies and mode shapes of pipeline are obtained with LMS data acquisition and analysis system, and the results are analyzed. By comparing the experimental modal and computational modal, it shows that computational modal analysis result is reliable and accurate, and the finite element model of the pipeline is verified to be correct.3. Through analyzing the stress of pipelines, computed the exciting force of liquid in the pipelines caused by pulsation, and vibration response of the pipeline are computed with finite element dynamics analysis. The pipeline's vibration response is tested with experimental method, and the test data and theoretical calculation results are compared and analyzed, and pipeline's vibration reduction measures are analyzed.