The Experts below are selected from a list of 2910 Experts worldwide ranked by ideXlab platform
Hui Chen - One of the best experts on this subject based on the ideXlab platform.
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ameliorated longitudinal critically Refracted attenuation velocity method for welding residual stress measurement
Journal of Materials Processing Technology, 2017Co-Authors: Qimeng Zhu, Guoqing Gou, Jia Chen, Hui ChenAbstract:This work aims at quantitative analysing the effect of different microstructures on the velocity at stress-free and stress coefficient (K) of longitudinal critical refraction (LCR) Wave in measuring welding residual stress process, ameliorating the traditional LCR Wave method for improving its’ effectiveness and accuracy. The longitudinal critically Refracted Wave attenuation velocity (LCR-AV) method was proposed in the evaluation of residual stresses in A7N01 welded joints. The same initial status base materials samples are used to produce different levels of grain size and precipitation by heat treatment technology, obtained the velocity at stress-free and attenuation of LCR Wave. As expected, the voltage amplitude changes linearly with velocity and stress coefficient, and the precipitation effect can be ignored. The LCR-AV method based on the liner relationship between velocity, attenuation and grain size are efficient to decrease the errors resulting from the different microstructure (base metals, heat-affected zones, and welded zones). Differ with the traditional LCR Waves method, the LCR-AV method also measures the voltage amplitude, and the measured results of LCR-AV method compared with those obtained by the hole-drilling reference method shows more sufficient measurement reliability and precision. It shows that LCR-AV method is a valuable quantitative technology to estimate the residual stress of welded joints.
Qimeng Zhu - One of the best experts on this subject based on the ideXlab platform.
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ameliorated longitudinal critically Refracted attenuation velocity method for welding residual stress measurement
Journal of Materials Processing Technology, 2017Co-Authors: Qimeng Zhu, Guoqing Gou, Jia Chen, Hui ChenAbstract:This work aims at quantitative analysing the effect of different microstructures on the velocity at stress-free and stress coefficient (K) of longitudinal critical refraction (LCR) Wave in measuring welding residual stress process, ameliorating the traditional LCR Wave method for improving its’ effectiveness and accuracy. The longitudinal critically Refracted Wave attenuation velocity (LCR-AV) method was proposed in the evaluation of residual stresses in A7N01 welded joints. The same initial status base materials samples are used to produce different levels of grain size and precipitation by heat treatment technology, obtained the velocity at stress-free and attenuation of LCR Wave. As expected, the voltage amplitude changes linearly with velocity and stress coefficient, and the precipitation effect can be ignored. The LCR-AV method based on the liner relationship between velocity, attenuation and grain size are efficient to decrease the errors resulting from the different microstructure (base metals, heat-affected zones, and welded zones). Differ with the traditional LCR Waves method, the LCR-AV method also measures the voltage amplitude, and the measured results of LCR-AV method compared with those obtained by the hole-drilling reference method shows more sufficient measurement reliability and precision. It shows that LCR-AV method is a valuable quantitative technology to estimate the residual stress of welded joints.
Tieyi Wang - One of the best experts on this subject based on the ideXlab platform.
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seismic Waveform classification and first break picking using convolution neural networks
IEEE Geoscience and Remote Sensing Letters, 2018Co-Authors: Sanyi Yuan, Shangxu Wang, Tieyi WangAbstract:Regardless of successful applications of the convolutional neural networks (CNNs) in different fields, its application to seismic Waveform classification and first-break (FB) picking has not been explored yet. This letter investigates the application of CNNs for classifying time-space Waveforms from seismic shot gathers and picking FBs of both direct Wave and Refracted Wave. We use representative subimage samples with two types of labeled Waveform classification to supervise CNNs training. The goal is to obtain the optimal weights and biases in CNNs, which are solved by minimizing the error between predicted and target label classification. The trained CNNs can be utilized to automatically extract a set of time-space attributes or features from any subimage in shot gathers. These attributes are subsequently inputted to the trained fully connected layer of CNNs to output two values between 0 and 1. Based on the two-element outputs, a discriminant score function is defined to provide a single indication for classifying input Waveforms. The FB is then located from the calculated score maps by sequentially using a threshold, the first local minimum rule of every trace and a median filter. Finally, we adopt synthetic and real shot data examples to demonstrate the effectiveness of CNNs-based Waveform classification and FB picking. The results illustrate that CNN is an efficient automatic data-driven classifier and picker.
Jia Chen - One of the best experts on this subject based on the ideXlab platform.
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ameliorated longitudinal critically Refracted attenuation velocity method for welding residual stress measurement
Journal of Materials Processing Technology, 2017Co-Authors: Qimeng Zhu, Guoqing Gou, Jia Chen, Hui ChenAbstract:This work aims at quantitative analysing the effect of different microstructures on the velocity at stress-free and stress coefficient (K) of longitudinal critical refraction (LCR) Wave in measuring welding residual stress process, ameliorating the traditional LCR Wave method for improving its’ effectiveness and accuracy. The longitudinal critically Refracted Wave attenuation velocity (LCR-AV) method was proposed in the evaluation of residual stresses in A7N01 welded joints. The same initial status base materials samples are used to produce different levels of grain size and precipitation by heat treatment technology, obtained the velocity at stress-free and attenuation of LCR Wave. As expected, the voltage amplitude changes linearly with velocity and stress coefficient, and the precipitation effect can be ignored. The LCR-AV method based on the liner relationship between velocity, attenuation and grain size are efficient to decrease the errors resulting from the different microstructure (base metals, heat-affected zones, and welded zones). Differ with the traditional LCR Waves method, the LCR-AV method also measures the voltage amplitude, and the measured results of LCR-AV method compared with those obtained by the hole-drilling reference method shows more sufficient measurement reliability and precision. It shows that LCR-AV method is a valuable quantitative technology to estimate the residual stress of welded joints.
Guoqing Gou - One of the best experts on this subject based on the ideXlab platform.
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ameliorated longitudinal critically Refracted attenuation velocity method for welding residual stress measurement
Journal of Materials Processing Technology, 2017Co-Authors: Qimeng Zhu, Guoqing Gou, Jia Chen, Hui ChenAbstract:This work aims at quantitative analysing the effect of different microstructures on the velocity at stress-free and stress coefficient (K) of longitudinal critical refraction (LCR) Wave in measuring welding residual stress process, ameliorating the traditional LCR Wave method for improving its’ effectiveness and accuracy. The longitudinal critically Refracted Wave attenuation velocity (LCR-AV) method was proposed in the evaluation of residual stresses in A7N01 welded joints. The same initial status base materials samples are used to produce different levels of grain size and precipitation by heat treatment technology, obtained the velocity at stress-free and attenuation of LCR Wave. As expected, the voltage amplitude changes linearly with velocity and stress coefficient, and the precipitation effect can be ignored. The LCR-AV method based on the liner relationship between velocity, attenuation and grain size are efficient to decrease the errors resulting from the different microstructure (base metals, heat-affected zones, and welded zones). Differ with the traditional LCR Waves method, the LCR-AV method also measures the voltage amplitude, and the measured results of LCR-AV method compared with those obtained by the hole-drilling reference method shows more sufficient measurement reliability and precision. It shows that LCR-AV method is a valuable quantitative technology to estimate the residual stress of welded joints.