管单元和壳单元管道系统动力有限元模型的对比分析

Pipeline vibration has an important influence on the safety and economic of industrial productions．The modal analysis of pipeline systems is an important way to understand the pipeline's dynamic characteristics and the main basis for the optimum design of pipeline systems．By the finite element modal analysis method，there are different element types that can be choose for the dynamic modeling of pipeline system. In order to understand the impact of different element types on the pipeline modal analysis results，the pipe element and shell element are employed to establish two kinds of pipeline's finite element model in ANSYS，the modal analysis of restraint and free system is carried on，and the empty pipeline testing is performed．Comparing the two kinds of finite element modal analysis results, it can be found that the natural frequencies of the pipe element modal are less than those of shell element modal, which was caused by the two different elements shape functions and the different constraint conditions. Contrasted to the experiment results, it is shown that the average error of the pipe element and shell element model results with the experimental is 3.83% and 3.14% respectively.