【摘要】 考虑海洋立管的实际服役环境和现有监测技术水平,发展一种基于应变响应统计特征的损伤诊断方法。推导以应变测量单元为基础的细长梁式结构应变响应与结构模态参数的映射关系,提出连续测试数据的均方根应变作为海洋立管的损伤特征参量。针对损伤程度较小或量测噪声影响较大可能引起的损伤误判,根据小波多分辨率分析理论,利用小波去噪和分解处理该损伤特征参量的空间域数据,进而实现准确地损伤定位。在此基础上,进行了某张力腿式平台顶部张紧式立管的数值模拟;依据损伤诊断策略对假定布设应变传感器的上部500个应变测量单元分析得到上述损伤特征参量。结果表明:该方法对立管局部刚度下降进行了有效的识别,对单、多处损伤的损伤判别和定位的效果良好,损伤诊断效果受量测噪声以及服役工况和顶张力等因素变化的影响较小,可为相关工程结构健康监测提供理论和技术支持。更多还原

【Abstract】 Considering the service environment and the monitoring technology level of offshore risers,a damage diagnosis method was developed based on statistical characteristics of strain responses. A mapping relation between modal parameters and strain responses of a strain-measured element was derived for a beam-like structure. A root mean square strain based on a set of test data was proposed as the damage characteristic parameter of offshore risers. Aiming at a plamage misjudging due to a lower level of damage or a larger measurement noise,the data were processed based on the wavelet de-noising and decomposition. Furthermore,a TTR on a TLP was simulated to obtain the damage characteristic parameter through analyzing 500 strain-measured elements at the top of the TTR. The results showed that the method can be used to identify the local stiffness dropping of the TTR effectively althrough the damage diagnosis is interfered by the measurement noise and other uncertain factors; the damage diagnosis strategy can provide a support for structural health monitoring both theoretically and technically.更多还原