【作者】 王刚；

【导师】 徐长航；

【作者基本信息】 中国石油大学(华东) ， 安全技术及工程， 2014， 硕士

【摘要】 自升式平台以其作业环境可变和作业状态多变等优点,在海洋石油的勘探与开发阶段起着关键性作用,但由于其可移动性和运动性的作业特点,以及综合海洋环境的复杂性和随机性等因素,自升式平台运行过程中极易形成结构的应力集中,导致承载能力下降从而诱发灾难事故,造成石油经济损失、环境污染等严重后果。金属磁记忆检测技克服传统无损检测的缺点,能够实现对铁磁性金属构件内部的应力集中区的快速检测,及早发现平台因结构损伤引起的安全隐患,防止突发性的疲劳损伤,具有重要的研究意义和工程应用价值。为了对自升式平台结构承载部件的金属磁记忆工程检测提供指导依据,在从结构破坏性及结构完整性两方面分析导致自升式平台结构应力集中因素的基础上,基于TSC-2M-8金属磁记忆检测设备及拉伸载荷实验系统,开展基于金属磁记忆检测技术的拉伸试件结构应力集中实验研究。基于俄罗斯动力诊断公司MMM-System金属磁记忆数据分析系统,分析拉伸试件在弹性、屈服、塑性及颈缩等不同应力阶段磁记忆信号的变化规律,研究拉伸试件结构应力集中的变化规律。以拉伸试件不同应力阶段的磁记忆检测信号为对象,应用小波分析法对原始检测数据进行滤波去噪,经对比分析选用db2小波作为小波分析基函数,分解尺度选择为4,阈值选用Heursure阈值可实现磁记忆信号的消噪。对消噪信号进行特征分析,最终确定检测信号最大值与最小值之间的差值Deta、检测信号的平均值H?p?,切向分量pxH的极值及法向分量pyH梯度值可作为结构应力集中判定的特征判据。最后,基于自升式平台模型室内检测实验的成果,以某自升式平台桩腿、吊机吊钩、平台甲板及悬臂梁区等结构承载部件为对象,进行实际的工程检测实验研究。结合不同构件的结构特点,从传感器选择的角度出发,提出相对应的金属磁记忆工程检测方法。对不同构件的检测数据进行工程检测分析,确定构件的应力集中程度,并对其安全可靠性进行评估,为自升式平台的结构健康检测工作提供参考依据。更多还原

【Abstract】 Jack-up platforms play a key role in offshore oil exploration and development because of its advantages of variable operating environment and changeable job status. However, due to the mobility and movement of its operating characteristics, as well as the complexity and randomness of marine environment and other factors, jack-up platforms will generate stress concentration of the structure in the process of running. As a result, the bearing capacity will decline, which will induce disasters and cause serious consequences petroleum economic losses and environmental pollution. Metal magnetic memory testing technology overcomes the shortcoming of the traditional nondestructive testing and can realize the rapid detection to stress concentration area of the ferromagnetic metal components. It has important significance and application value for early detection of security risks due to structural damage and sudden fatigue damage prevention.In order to provide guidance basis for jack-up platform bearing parts metal magnetic memory engineering detection, based on the analysis of jack-up platform structure stress concentration factors from two aspects of structural destructive and structural integrity, the experimental study of tensile specimen structure stress concentration detection on the basis of metal magnetic memory testing technology with the use of TSC-2M-8 metal magnetic memory testing equipment and tensile load test system. The tensile specimen magnetic memory signals of the different stress stages(elasticity, yield, plasticity and necking) was analyzed, and the MMM signals changing rule was summarized.With tensile specimen magnetic memory testing signals of different stress stages as the object, wavelet analysis was used for the original test data filtering noise. Through comparative analysis, db2 wavelet was selected as the wavelet function, and the wavelet decomposition scale was 4, and the threshold selection is Heursure threshold. The feature analysis was executed to the de-noised signals, and finally the difference between the minimum and maximum Tensile Specimen MMM signal value Deta, MMM signal average value H? p?, MMM tangential component signal pxH extreme value and MMM normal component signal pyH gradient value py?H were determined to be the characteristic criteria of structure stress concentration.Finally, based on the results of indoor jack-up platform model test, taking one jack-up platform structure bearing components legs, crane hook, deck and cantilever beam section as objects, the actual engineering test researches were conducted. Combined with the structure characteristics of different components, from the perspective of sensor selection, corresponding metal magnetic memory detection methods were put forward. Engineering test analysis was carried out based on the testing data of different components. The degree of structure stress concentration was confirmed and its safety and reliability were evaluated, which will provide the reference basis to the jack-up platform structural health inspection.更多还原