Stochastic Finite-Element Modeling and Dynamic Characteristics Analysis of Pipe-Conveying Fluid

Abstract

Randomness of fluid and structure properties inherently exists in actual pipes. The waves of parameters may play a significant role in the pipeline dynamic characteristics. However, the vibration analysis of pipe-conveying fluid is usually done by considering the deterministic parameters. To overcome the limitation, a stochastic dynamic model is proposed for the dynamic characteristics analysis of pipe-conveying fluid. Considering the uncertain fluid and structure properties described as one-dimensional stochastic field function, a stochastic dynamic pipeline model based on the stochastic finite element is presented for three-dimensional dynamic characteristics analysis in this paper. A stochastic analytical formula is deduced to obtain the statistical results of the structural dynamic characteristics and responses of pipeline with random properties. The statistics obtained from the presented model are compared with the prior experimental data and Monte Carlo simulation so as to validate the presented model and analysis method, and good agreement is obtained. Effects of structure and fluid randomness are studied in linear and nonlinear pipeline systems, respectively. It is found that the effects of random properties on pipeline eigenvalue and dynamic response are significant, especially the influences of the random elastic modulus, density and flow velocity.