基于小波包分析的随机海洋环境下平台结构损伤辨识

为确保海洋平台作业安全,及时辨识损伤以及进行损伤定位,须进行海洋平台结构健康监测。以某在役导管架平台为例,对其数值模型进行结构动力分析。利用小波包变换方法处理结构响应信号,提取各分节点小波包能量,并研讨小波包分解层数,提出一种基于测点能量标准差的指标,以达到辨识结构损伤的目的。结果表明构建指标可在一定程度上弱化环境影响,提高损伤辨识精度。在7层小波包分解下利用测点能量标准差作为指标,可对随机波浪条件下的结构损伤进行有效辨识。

Damage Identification of Platform Structure Under Random Wave Conditions Based on Wavelet Packet Transformation

In order to ensure that the offshore platform can operate safely and the damage can be identified and located in time,the structural health monitoring of the offshore platform is important.The dynamic response of the numerical model of a certain jacket platform in service is analyzed.The wavelet packet transformation method is used to decompose the structure response signals,the energy of the nodes is extracted,the number of the decomposition layer is discussed,and an index based on the standard deviation of the measuring point energy is proposed.The results show that by constructing indicators,the impact of the environment can be weakened and the accuracy of the damage identification can be improved to some extent.Using the standard deviation of the measuring point energy under seven layer wavelet packet transformation as an index,the structural damage under random wave conditions can be effectively identified.