共查询到19条相似文献,搜索用时 203 毫秒
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针对油气长输管道外壁缺陷影响管道安全运行的问题,提出了一种基于动生涡流磁场的无损检测方法。借助ANSYS Electronics有限元分析软件分析了管道表面缺陷参数、检测速度与动生涡流磁场之间的关系,发现在不同管道表面缺陷参数下,动生涡流磁场会根据缺陷形状、尺寸的差异反馈出不同的磁感应强度信号,缺陷尺寸越大,信号反馈越强烈;随着检测速度的提高,动生涡流的磁感应强度逐渐增大,但整体变化趋势基本一致。根据工程实际研制了基于动生涡流磁场的管道无损检测试验装置,开展了试验研究,得到了与仿真相同的规律性结果,从而验证了该技术的可行性,表明动生涡流磁场无损检测方法能够对管道缺陷进行精准定位与辨别。 相似文献
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《全面腐蚀控制》2021,(6)
针对解决地面钢质管道的损伤检测问题,提出一种基于涡流磁场检测原理的无损检测技术,设计了新型检测探头和矫正探头组成差分结构,对探头参数进行计算,优化探头结构,搭建实验平台,完成了一种涡流磁场管道检测系统设计。采用有限元仿真研究方法,分析了在检测探头激励磁场的作用下,管道在缺陷处的三轴磁场变化规律及电势变化情况。通过开展室内实验研究,分析了管道存在不同种类缺陷时,其缺陷处磁感应强度变化规律,应用物理方法提取出不同种类缺陷信号,使缺陷直观突显。研究结果表明:设计的一种基于涡流磁场地面钢质管道损伤检测系统可以实现对管道损伤的有效检测,且能够保证一定的提离距离。 相似文献
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以压力容器等焊接设备对接焊缝为对象,提出了一种基于数值模拟的焊缝缺陷漏磁场的分析方法。通过仿真分析,对比分析了不同焊接工艺(单面焊和双面焊)无缺陷、焊道上分布矩形槽缺陷及热影响区分布矩形槽缺陷时的漏磁场特征,评述了单面焊同时分布两个矩形槽缺陷对漏磁场分布的影响规律。数值模拟结果表明:双面焊这种结构对于焊道上分布矩形槽时的漏磁场的影响更大;两个缺陷同时存在时,缺陷之间的距离是影响缺陷漏磁场分布的主要因素。 相似文献
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利用ANSYS有限元软件模拟了3种不同缺陷形状在不同参数下对于漏磁场的影响。分析了漏磁场径向分量以及轴向分量在不同参数下的变化曲线,根据其变化趋势选取了合适的特征值,为实现智能化识别缺陷提供了基础。分别建立了矩形凹槽、平滑凹坑和穿孔3种不同缺陷的漏磁场三维ANSYS模型,分别改变其磁化装置的气隙高度、缺陷宽度和缺陷深度3种参数,得到3种不同缺陷的漏磁场轴向曲线与径向曲线,分析研究了3种参数对于漏磁场的影响,根据其变化趋势选取了4种不同的特征值,通过t-SNE算法对4种不同特征值进行降维可视化,将其从高维空间降维至二维空间,验证了所选取的4种特征值能够明显地区分不同的缺陷类型,为通过计算机实现智能化识别缺陷类型提供了基础。 相似文献
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飞机发动机叶片基体出现裂纹时表面反映不明显,孔探仪检查表面裂纹实际判别的难度较大,因此用交变磁场非接触式探测法探测。介绍探伤原理、特点以及与其它无损检测方法的比较,最后给出了发动机叶片的检测实例。检测结果表明,该方法检出的大小裂纹的波形与实际裂纹相符甚好,因此较传统涡流法和孔探仪法更具优越性,具有实际应用价值。 相似文献
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Structural optimization of 2-D array probe for alternating current field measurement 总被引:1,自引:0,他引:1
A double U-shaped orthogonal inducer for the alternating current field measurement (ACFM) is presented, which could extend the limitation of the direction of tested cracks and decrease the loss of magnetic flux compared to the single rectangular inducer. The structure of the testing probe was optimized to meet the expectations of the pointwise magnetic field measurement and to decrease every group of coils’ space by orthogonally winding method, and the two-dimensional (2-D) ACFM probe array was designed. The detection precision and lift-off effect of the 2-D ACFM probe array were experimentally studied. The results show that the relative error of this probe is less than 10%, and it could suppress the lift-off disturbance effectively, which makes this 2-D ACFM probe array to be insensitive to lift-off and unable to meet the engineering expectations. 相似文献
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近海水下结构无损检测新技术 总被引:1,自引:1,他引:1
结合海洋平台安全检测的实际需要,简要介绍国内外水下无损检测技术的研发现状,重点是近几年发展起来的水下无损检测新技术,主要包括交流电场测量法(ACFM)、电场特征检测法(FSM)、进水构件测试法(FMD)以及水下成像技术等,对其在我国的应用前景进行了评估。最后,针对目前我国水下无损检测存在的一些问题,对其未来的发展进行了展望。 相似文献
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Alternating current field measurement (ACFM) technology has been used for sizing underwater structure cracks. However, conventional ACFM is more sensitive to cracks perpendicular to the induced current than cracks with other angles. In this paper, a rotating alternating current field measurement (RACFM) method and underwater test system are present for the detection of arbitrary-angle cracks with high sensitivity. The RACFM is proved by simulations and experiments. Arbitrary-angle cracks detection results obtained from ACFM and RACFM have shown that the RACFM method overcomes the limitation of directional detection of ACFM and effectively achieves high detection sensitivity for arbitrary-angle cracks on underwater structures. 相似文献
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According to the principle of the alternating current field measurement (ACFM), the inducing frequency has a significant influence on the signal acquisition and the measurement accuracy of an ACFM system. To design an ACFM prototype system with a U-shaped probe, the inducing frequency of the ACFM system is determined through simulation analysis and an experimental study in this paper. A large number of simulations are designed and run to analyze the influences of the inducing frequency on characteristic vectors of the induction electromagnetic field. By analyzing the simulation results, 6 kHz is selected to be the optimal inducing frequency for the U-shaped probe of an ACFM prototype. This frequency is tested by real crack inspection experiments using the U-shaped probe of the ACFM prototype in laboratory. The results show that 6 kHz is appropriate to realize the crack inspection and sizing with reasonable accuracy. The result in this paper will benefit the design and manufacturing of the prototype for the U-shaped probe ACFM system. 相似文献
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Reza Khalaj Amineh Maryam Ravan S.H. Hesam Sadeghi Rouzbeh Moini 《NDT & E International》2008,41(3):169-177
We propose a model-based inversion method to size long surface-breaking cracks in ferrous metals using alternative current field measurement (ACFM) data at an arbitrary liftoff distance. This method employs conjugate gradients optimization to invert measured surface ACFM signal to crack depth. To alleviate the adverse effect of sensor liftoff uncertainty on crack sizing, we propose a blind de-convolution algorithm for reconstructing respective surface ACFM crack signal. In this algorithm, the partially known filter function associated with the sensor liftoff is estimated from which the surface crack signal can be restored. The validity of the proposed inversion method is demonstrated by comparing the actual and predicted depths of several simulated and machine-made long cracks in mild steel test blocks. 相似文献