海洋平台损伤诊断研究

Damage Diagnosis Research on Offshore Platform

结合动力学和有限元方面的知识,以杭州湾跨海大桥海洋平台为背景,分别从固有频率和应变能损伤因子两个方面对损伤进行评估和定位。然后基于平台的工作环境,考虑了波浪力、水流力和阻尼等作用因素,进行了非线性动力响应分析,根据位移和截面应变变化率的变化情况进行损伤诊断。同时从概率论的角度上考虑了随机波浪力荷载,通过对所测波浪力荷载的统计,算出功率谱密度函数,然后计算了此荷载下结构的动力响应,并用应变均方根的变化值来检测结构的损伤和损伤程度,最后为今后大型海洋平台的损伤诊断提出建议和方法。

According to the dynamics and finite element method and based on Hang-Zhou Bay Sea-Crossing Bridge offshore platform, the estimation and localization on damage were carried out in terms of the natural frequencies and damage factor of modal strain energy. Considering the wave force, current force, damping and so on, the analysis of nonliear dynamic response was proceeded by a commercial software. The damage diagnosis was performed through the variation amplitued of displacement and changing rate of cross-section strain. The wave force and a random load were considered in the probability method, the power spectral density function was calculated by the statistics of measured wave force, and then the dynamic response of the platform was obtained. The mean square root of stain was used to detect the damgae. Finally, suggestions and methods were put forward for the future damage diagnosis on complex off shore platform.