Buckling Analysis on a Pipe Conveying Fluid under Two Stresses

某输流管道两种管壁应力作用下的屈曲分析

¹ School of Mechanical Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China
² School of Mechanics, Civil Engineering and Architecture, Northwestern Polytechnical University, Xi'an 710129, China

Received: 12 June 2017

Abstract

Pressure pipes have broad applications in aviation, space flight, mechanical engineering, industrial and civil architecture etc. Instability destruction is their main failure mode. Firstly, in this paper, a complex fluid-solid coupling problem was simplified as a buckling problem of a pipe under two stresses which were along the pipe wall. The two stresses consisted of a compressive stress which was perpendicular to the pipe wall and a tangential stress which was parallel to the pipe wall. Secondly, the buckling performs of the pressured pipe were discussed by finite element analysis method under a working state and an off-working state, respectively. Some obtained conclusions were drawn as follows by the analysis in this paper.1). Provided the tangential stress is unchanged, by increasing compressive stress eigenvalue buckling critical load increases and nonlinear buckling critical load decreases.2). Provided the compressive stress is unchanged, when the direction of the tangential stress is same as that of the axial pressure, by increasing the absolute value of tangential stress the buckling critical load decreases; provided the compressive stress is unchanged, when the direction of the tangential stress is in the opposite direction of the axial pressure, by increasing the absolute value of tangential stress the buckling critical load increases.

摘要

压力管道在航空、航天、机械工程、工业与民用建筑领域以及其他领域有着广泛的应用，失稳屈曲是其主要失效形式之一。首先将复杂的流固耦合问题简化为2种管壁应力作用下的管道屈曲问题。这2种应力是指：垂直于管壁的压应力和平行于管壁的切应力。其次，采用有限元方法分析了压力管道工作状态和非工作状态的屈曲性能。通过求解和分析，得出以下主要结论：第一，切应力不变，随着压应力的增大特征值屈曲临界载荷增大，而非线性屈曲临界载荷减小。第二，压应力不变，切应力与轴向压力方向相同时，随着切应力绝对值增大，屈曲临界载荷减小；切应力与轴向压力方向相反时，随着切应力绝对值增大，屈曲临界载荷增大。