共查询到20条相似文献，搜索用时 31 毫秒
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M. M. Ettefagh 《海洋工程》2015,29(6):891-902
Damage identification of the offshore floating wind turbine by vibration/dynamic signals is one of the important and new research fields in the Structural Health Monitoring (SHM). In this paper a new damage identification method is proposed based on meta-heuristic algorithms using the dynamic response of the TLP (Tension-Leg Platform) floating wind turbine structure. The Genetic Algorithms (GA), Artificial Immune System (AIS), Particle Swarm Optimization (PSO), and Artificial Bee Colony (ABC) are chosen for minimizing the object function, defined properly for damage identification purpose. In addition to studying the capability of mentioned algorithms in correctly identifying the damage, the effect of the response type on the results of identification is studied. Also, the results of proposed damage identification are investigated with considering possible uncertainties of the structure. Finally, for evaluating the proposed method in real condition, a 1/100 scaled experimental setup of TLP Floating Wind Turbine (TLPFWT) is provided in a laboratory scale and the proposed damage identification method is applied to the scaled turbine. 相似文献
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《中国海洋工程》2015,(6)
Damage identification of the offshore floating wind turbine by vibration/dynamic signals is one of the important and new research fields in the Structural Health Monitoring(SHM). In this paper a new damage identification method is proposed based on meta-heuristic algorithms using the dynamic response of the TLP(Tension-Leg Platform) floating wind turbine structure. The Genetic Algorithms(GA), Artificial Immune System(AIS), Particle Swarm Optimization(PSO), and Artificial Bee Colony(ABC) are chosen for minimizing the object function, defined properly for damage identification purpose. In addition to studying the capability of mentioned algorithms in correctly identifying the damage, the effect of the response type on the results of identification is studied. Also, the results of proposed damage identification are investigated with considering possible uncertainties of the structure. Finally, for evaluating the proposed method in real condition, a 1/100 scaled experimental setup of TLP Floating Wind Turbine(TLPFWT) is provided in a laboratory scale and the proposed damage identification method is applied to the scaled turbine. 相似文献
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提出将基于动态特性的检测方法与局部物理检测手段相结合的探伤思路。利用动力学方法进行实时监测及损伤区域的粗略定位,再由物理探测方法实现损伤程度和位置的精确判断,从而降低对动态检测方法的精度要求。此外,文中尝试直接由结构的动力响应信号构建能量指标识别结构损伤的方法,不需要进行模态参数识别,算法简单,有望应用于海洋平台、高层建筑等可简化为串联多自由度体系的结构的实时监测和损伤初步定位。 相似文献
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Jason D. Tambie Madiha Farag-Miller Keith Miller Bheshem Ramlal Michael Sutherland 《Marine Geodesy》2019,42(3):227-245
Using two dimensional continuous wavelet transforms, a novel method for identification of mesoscale eddies is presented to facilitate extraction of characteristics for area, amplitude, type, and location from maps of sea level anomalies. In comparison with the previously established growing method for eddy identification, it is found that the wavelet method identifies more than twice the number of eddies and is particularly better at resolving small eddies down to the 0.25 degree resolution of the data. Such research into eddy identification and tracking is significant to the assessment of eddies with potential to impact on coastlines of small islands. The method is applied to the identification of eddies on tracks towards islands of the Eastern Caribbean over 23?years. Spatial and temporal variation in rate of occurrence and magnitude is established. For Barbados there is an average of 9 anticyclonic incidents a year with maximum amplitude of typically 0.22?m in the dry seasons and 0.16?m in the wet seasons. Seasonal variation is reversed for the other islands with twice the number of anticyclonic incidents having maximum amplitudes of about 0.20?m annually. 相似文献
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多环芳烃油指纹应用于船舶溢油鉴别研究 总被引：2，自引：0，他引：2
溢油种类主要包括船舶燃料油和原油,二者性质的差异决定了鉴别方法也相应不同,寻求适合于船舶溢油的鉴别方法具有重要意义。在使用柱色谱层析方法对样品进行分离前处理的基础上,以气相色谱/质谱方法(GC-MS)为主要分析手段,对溢油样品和可疑船舶溢油源样品的多环芳烃油指纹特征进行对比,并在多环芳烃油指纹参数的基础上进一步进行多环芳烃内组成三角图分布特征与聚类分析研究,成功为珠江口水域某船舶溢油事故追踪到肇事溢油源。结果表明:取自丁船的油样和现场溢油样芳烃油指纹特征最为相近,是此次溢油事故的溢油源。受风化作用后的船舶燃料油中饱和烃类化合物数量稀少,且含量极低,不适合用于溢油鉴别,而多环芳烃类化合物较饱和烃类化合物而言具有含量高、种类丰富的特点,是该类溢油鉴别的主要油指纹依据。使用油指纹参数进行可疑溢油源识别时,充分考虑油品中有机分子所受风化影响程度的不同是风化条件下溢油鉴定的关键。因此,多环芳烃油指纹可以有效应用于船舶燃料油溢油的鉴别。 相似文献
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The purpose of this paper is to identify the functional form of the nonlinear roll damping for a particular ship based on an experiment. The problem of damping identification is formulated as an integral equation of the first kind. However, the solution of the problem lacks stability properties, due to the ill-posedness of the first-kind integral equation. To resolve this problem, a stabilization technique (known as a regularization method) is applied to the present problem of the identification of nonlinear damping. The identified results for nonlinear roll dampings are compared with those from a conventional roll identification method. The findings of the present study are validated by the direct comparison of experimental data on free-roll decay motion with the numerically simulated results. 相似文献
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讨论了使用Froude法和Faltinsen法识别线性和非线性阻尼系数时的系统误差。通过回顾两种方法的推导过程,论证了方法的内在假设,并量化两种方法的系统误差。为减少识别过程误差,文中提出了直接积分法,并依据数值与试验数据,讨论了3种识别方法识别结果。结果表明,Froude法相比于Faltinsen法能更好地预报线性和非线性阻尼系数。对于低阻尼浮体问题,Froude法和Faltinsen法可以给出相对准确的预测,而对于强阻尼浮体问题,Froude法与Faltinsen法在确定的线性和非线性阻尼系数中会给出大于5%的系统误差,而直接积分法展示了较高的识别精度。 相似文献
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In order to predict the roll motion of a floating structure in irregular waves accurately, it is crucial to estimate the unknown damping coefficients and restoring moment coefficients in the nonlinear roll motion equation. In this paper, a parameter identification method based on a combination of random decrement technique and support vector regression (SVR) is proposed to identify the coefficients in the roll motion equation of a floating structure by using the measured roll response in irregular waves. Case studies based on the simulation data and model test data respectively are designed to validate the applicability and validity of the identification method. Firstly, the roll motion of a vessel is simulated by using the known coefficients from literature, and the simulated data are used to identify the coefficients in the roll motion equation. The identified coefficients are compared with the known values to validate the applicability of the identification method. Then the roll motion is predicted by using the identified coefficients. The prediction results are compared with the simulated data, and good agreement is achieved. Secondly, the model test data of a FPSO are used to identify the coefficients in the roll motion equation. Then the random decrement signature of the roll motion is predicted by using the identified coefficients and compared with that obtained from the model test data, and satisfactory agreement is achieved. From this study, it is shown that the identification method can be effectively applied to identify the coefficients in the nonlinear roll motion equation in irregular waves. 相似文献
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HY-2卫星散射计热带气旋自动识别算法 总被引：2，自引：1，他引：1
对基于HY-2卫星散射计风矢量产品的热带气旋自动识别算法进行了研究。算法分为粗搜索与精搜索两部分。粗搜索利用热带气旋风场的风速与风向分布直方图特征确定搜索的阈值,快速剔除比较容易识别的非热带气旋区域。在此基础上,精搜索利用热带气旋风向的螺旋状分布特征,通过搜索目标区域内是否存在螺旋状流线的方法,确定目标区域的风向是否存在螺旋状流线特征,从而实现对热带气旋的准确自动识别。作为示例,将该方法应用到对HY-2散射计观测到的2012年6号强热带风暴"杜苏芮"的自动识别,结果表明,本文提出的算法可以从HY-2散射计风场数据中准确有效的自动识别出热带气旋。 相似文献
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In the identifying process of an oil spill accident, manual integral and artificial visual comparison are commonly used at present to determine the oil spill sources, these methods are time-consuming and easily affected by human factors. Therefore, it is difficult to achieve the purpose of rapid identification of an oil spill accident. In this paper, an intelligent method of automatic recognition, integration and calculation of diagnostic ratio of Gas Chromatography-Mass Spectrometer (GC/MS) spectrum are established. Firstly, four hundreds of samples collected around the world were analyzed using a standard method and Retention time locking technology (RTL) was applied to reduce the change of retention time of GC/MS spectrum. Secondly, the automatic identification, integration of n-alkanes, biomarker compounds, polycyclic aromatic hydrocarbons and calculation of the diagnostic ratios were realized by MATLAB software. Finally, a database of oil fingerprints were established and applied successfully in a spill oil accident. Based on the new method and database, we could acquire the diagnostic ratios of an oil sample and find out the suspected oil within a few minutes. This method and database can improve the efficiency in spilled oil identification. 相似文献
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针对海上油气平台信息不足的问题,开展多源卫星遥感的油气平台识别方法研究。基于Landsat-8光学遥感影像(2018—2021年)应用阈值分割法、K-means分类法和最大似然分类法分别识别出渤海海域油气平台136座、166座和113座;基于Sentinel-1 SAR影像(2018—2021年)应用阈值分割法识别出油气平台338座;对上述结果进行决策级融合,识别出渤海油气平台428座。利用ZY-3高分辨率影像对融合方法的识别结果进行验证,结果显示识别油气平台的正确率达到85.2%,错判率、漏判率分别为10.9%和3.9%;油气平台位置与相关文献和公开资料一致。研究结果表明,决策级融合方法能够实现海上油气平台的有效判别,具有推广、应用价值。 相似文献
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Dynamic Load Identification in Time Domain 总被引：1，自引：0，他引：1
Chu Liangcheng Qu Natsi Wu Ruifeng Lu Min Yang Guojin Assistant M. S. Dalian University of Technology Dalian
Associate Professor Dalian University of Technology Dalian
Professor Dalian University of Technology Dalian
Engineer Bohai Oil Company
Senior Engineer Bohai Oil Company 《中国海洋工程》1991,(3)
- In the time domain method the dynamic load is successfully identified when the accelerations, velocities and displacements or velocities and displacements of the structure are known. But in engineering practice or experiments usually only the acceleration response is recorded. In this paper an improved time domain method is proposed for dynamic load identification. In this method by using of Duhamel integral, only the acceleration response is required for load identification. As an application of the present method, the dynamic ice load on a Bohai offshore platform is identified based on some measured acceleration. The identified values of ice load are in good agreement with the measured ones. 相似文献
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赤潮藻鉴定与定量检测方法进展 总被引：2，自引：0，他引：2
从基于形态学差异的图像识别技术、基于核酸分析的检测方法、基于免疫分析的检测方法、基于特征色素的方法和基于光学特性的方法5个方面,比较系统地回顾了有关赤潮藻定性鉴定和定量检测技术的发展,并就存在的问题和发展趋势作了简要分析。 相似文献
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This paper reports the approach and results of calibrating a two-dimensional hydrodynamics model. The model was applied to Humboldt Bay, California, and calibrated with synoptic tidal data at four locations. The model calibration was done by using both a trial-and-error approach and a parameter identification (PI) method. For the given finite-difference grid resolution and field observations, the calibration attempt revealed that the two methods produced two different sets of parameters, but with almost identical comparisons between the model solutions and observations. The study results indicate that the appropriate range of model parameter values can be more efficiently identified by parameter identification method, and the best calibration strategy is to use both methods conjunctively. 相似文献
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A lumped parameter model of open-frame unmanned underwater vehicles (UUV's) including the effects of propeller-hull and propeller-propeller interactions is presented. The identification of the model parameters consists of a least squares method using only on-board sensor data without requiring any towing tank tests. The identification scheme is based on separate tests for the estimation of drag and thruster installation coefficients, taking into account propeller-hull and propeller-propeller effects first and inertia parameters subsequently. The scheme has been experimentally implemented on ROMEO, the latest UUV developed by CNR-IAN. Experimental results show both the effectiveness of the proposed method and the relevance of the propeller-hull and propeller-propeller interactions that are usually neglected in standard UUV models 相似文献
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基于阵列感应测井的支持向量机流体识别方法 总被引：3，自引：0，他引：3
基于研究区块的高分辨率阵列感应测井(HDIL)资料,首先分析了利用交会图法进行流体识别的效果,指出了该常规解释方法的局限性。在此基础上,将基于遗传算法优化的支持向量机(GA-SVM)引入到测井解释当中,结合阵列感应测井和常规测井资料,建立了流体识别的非线性模型。利用该模型对45个训练样本进行回判,准确率为100%,对21个预测样本进行预测的准确率为90.48%,相对于常规解释方法,该流体识别方法具有更高的准确率。 相似文献
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基于AHP法和灰色模式识别理论的海底管道系统路由定量风险评估 总被引：3，自引：1，他引：3
根据海底管道路由潜在风险的特点及风险类型,提出了一种将层次分析法（AHP法）和灰色模式识别理论相结合的海底管道系统路由定量风险评估方法,该方法利用AHP确定风险评价指标体系,运用灰色模式识别理论,建立识别结果标准,并结合实际工程进行计算,计算结果表明该方法是可行的. 相似文献