随机波浪作用下海洋平台响应分析与结构优化设计  

RESPONSE ANALYSIS AND OPTIMIZATION OF JACKET OFFSHORE PLATFORMS UNDER RANDOM WAVE LOAD

作　　者：马红艳[1] 刘书田[1] 顾元宪[1] 张文首[1] 

机构地区：[1]大连理工大学工程力学系,工业装备结构分析国家重点实验室,大连116024

出　　处：《工程力学》2005年第1期129-134,共6页Engineering Mechanics

基　　金：国家自然科学基金项目(10032030; 59895410);国家重点基础研究专项经费项目(G1999032805)

摘　　要：根据随机响应分析的确定性算法,提出了随机波浪作用下海洋平台结构响应灵敏度分析方法。采用虚拟激励算法,将随机响应灵敏度分析问题转化为稳态简谐响应分析,进一步求出结构随机响应的均值、方差、协方差等统计量的灵敏度。这一过程可直接利用响应分析的程序模块,避免计算振型导数的困难,具有较高的计算效率和精度。与差分法计算结果的比较验证了该方法的效率和精度。在此基础上,研究了随机波浪作用下海洋平台结构尺寸与形状优化方法。本文方法在有限元分析与优化设计软件系统JIFEX中实现,数值算例验证了算法的有效性。A method of sensitivity analysis for random responses of offshore platforms under wave forces is proposed in the paper. Based on a deterministic approach - the Pseudo Excitation Method (PEM), the sensitivity analysis of random responses is transformed into stationary harmonic response analysis. Furthermore, the sensitivities of the statistic properties, such as the standard deviations, the mean values and the covariance of the random responses are obtained. The sensitivity equations are solved by utilizing directly the program module of response analysis, avoiding the difficulty in calculating derivatives of eigenvectors and enhancing the computational efficiency. The comparison with the finite difference method verifies the accuracy and efficiency. Based on the sensitivity analysis method, the design optimization of offshore platform structures subject to random wave loads with size and shape design variables is investigated. The sequential linear programming algorithm together with some modification techniques, such as the adaptive move limit, the approximate line search and the approximate reanalysis, is used to solve the optimization problem. The proposed method has been implemented in the finite element analysis and design optimization software - JIFEX. An offshore platform structure is studied to demonstrate the effectiveness of the method.

关 键 词：海洋平台 随机波浪 灵敏度 结构优化 虚拟激励法 

分 类 号：TU311.3[建筑科学—结构工程]