考虑几何非线性海底悬跨管道随机振动分析方法.pdfVIP

第 26 卷第 10 期 Vol.26 No.10 工 程 力 学 2009 年 10 月 Oct. 2009 ENGINEERING MECHANICS 233 文章编号：1000-4750(2009)10-0233-07 考虑几何非线性海底悬跨管道随机振动分析方法 * 何 勇， 龚顺风，金伟良 (浙江大学结构工程研究所，浙江，杭州 310027) 摘 要：考虑海底悬跨管道的几何非线性特征，建立了悬跨管道非线性随机振动响应分析方法。该方法结合模态 分析，首先把系统隐式的非线性项转化为由模态坐标高次组合表示的显式非线性项，在此基础上引入虚拟激励法， 建立结构在随机流力作用下的等效线性化系统，从而确定结构非线性随机响应。通过对某一海底管道的分析结果， 表明该方法能够有效的考虑几何非线性的影响且具有很高的计算效率。同时分析了悬跨长度、管道外径和残余应 力因素对计算结果的敏感性。结果表明：当悬跨长度达到较大跨度后，忽略结构几何非线性的影响，将会导致较 大的误差；在较大的跨距、较浅的水深、较小的外径、初始压应力这些因素下，管道响应幅值较大。因此在这些 因素存在时，要引起高度的关注。 关键词：海底悬跨管道；随机振动；几何非线性；等效非线性系统；虚拟激励法 中图分类号：P756.2 文献标识码：A NONLINEAR RANDOM VIBRATION OF FREE SPANNING SUBMARINE PIPELINE CONSIDERING THE GEOMETRICAL NONLINEARITY * HE Yong , GONG Shun-feng , JIN Wei-liang (Institute of Structural Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China) Abstract: By considering the geometrical nonlinearity, a new method for the nonlinear random vibration of a free spanning submarine pipeline is presented. Firstly, using modal analysis, the implicit system is represented as an explicit nonlinear system whose nonlinear terms are based on the combination of modal coordinates. Secondly, using the pseudo-excitation method, the stochastic equivalent linear system is established. Based on the equivalent linear system, the nonlinear response of the pipeline can be gained conveniently. The proposed method is used in the analysis of a suspended pipeline. The results show that the method can consider geometric nonlinearity and has high efficiency. The influences of the spans, water-depths, diameters and residual stresses are analyzed. The results