基于振动与声发射信息融合的海洋平台损伤定位方法实验

目前我国海洋平台特别是进入中后期服役阶段海洋平台的安全问题越来越成为制约其正常作业的重要因素。为保证平台服役期间的安全运行，以海洋平台模型为实验对象，通过预制损伤等物理手段模拟平台的不同状态，进行了基于振动与声发射信息融合的结构损伤定位分析实验。①振动定位法实验，经滤波后采用细化FFT法进行信号处理，分析了海洋平台模型完好与损伤状态下信号幅值变化率与损伤位置的对应关系，结果表明：振动法可以在垂直方向上确定损伤位置。②声发射定位法实验，通过确定能量计数的变化与损伤位置之间的对应关系，结果表明：声发射法可以在水平方向上确定损伤位置。③通过对上述两种方法进行信息融合，实现了对海洋平台整体进行损伤定位。④最后通过海洋平台状态监测模型进行了实验验证。结论认为，该损伤定位方法具有较高的可靠度与精确度，可以实现平台损伤的有效定位。

An experimental study of damage detection/location methods in offshore platforms using vibrations and acoustic emission data

The security problem has become one of the important factors restricting the normal production of Chinese offshore platforms especially at their mid to late service period. In view of this, with an offshore platform as an experimental subject, different states of the platform were simulated by means of physical methods such as pre strain damage. On this basis, an experimental study was conducted of the positioning analysis of structural failures in fixed offshore platforms by use of both vibrations and acoustic emission information. First, with the vibration based positioning analysis method, the post filtered signal was processed by the detailed Fast Fourier Transform (FFT) algorithm; the correspondence was then analyzed between the signal amplitude varying ratio and damage position under the good and damage conditions of the offshore platform, thus to help identify the damage position vertically. Second, with the acoustic emission based analysis method, acoustic emission energy and energy rate parameters were found to be related to ductile/brittle fracture mechanisms and acoustic emission activity, thus, the damage position was determined horizontally. Third, through the information fusion by the above two methods, damage detection/location was thus achieved for the structural failures in fixed offshore platforms. Finally, the above two experimental analysis methods were validated in pilot tests through the condition monitoring model of offshore platforms. In the end, this paper concludes that the above methods are of high reliability and accuracy and can realize the effective damage detection and location for structural failures in fixed offshore platforms.