The ground roll and body wave usually show significant differences in arrival time, frequency content, and polarization characteristics, and conventional polarization filters that operate in either the time or frequen...The ground roll and body wave usually show significant differences in arrival time, frequency content, and polarization characteristics, and conventional polarization filters that operate in either the time or frequency domain cannot consider all these elements. Therefore, we have developed a time-frequency dependent polarization filter based on the S transform to attenuate the ground roll in seismic records. Our approach adopts the complex coefficients of the S transform of the multi-component seismic data to estimate the local polarization attributes and utilizes the estimated attributes to construct the filter function. In this study, we select the S transform to design this polarization filter because its scalable window length can ensure the same number of cycles of a Fourier sinusoid, thereby rendering more precise estimation of local polarization attributes. The results of applying our approach in synthetic and real data examples demonstrate that the proposed polarization filter can effectively attenuate the ground roll and successfully preserve the body wave.展开更多
To meet the demand of the pressure vessel industry, Baosteel has developed an S11306 ＋ SA516Gr70 roll-bonded clad steel plate. Comprehensive inspections of the composition, microstructure, and properties are performe...To meet the demand of the pressure vessel industry, Baosteel has developed an S11306 ＋ SA516Gr70 roll-bonded clad steel plate. Comprehensive inspections of the composition, microstructure, and properties are performed to systematically evaluate the steel plate in normalized state and normalized ＋ stress relieved state. The results show the cladding interface of the Sl1306 ＋ SA516Gr70 roll-bonded clad steel plate has high shear strength, and the base metal has good mechanical properties. The performance is fully consistent with the technical requirements of the roll-bonded clad steel plate for pressure vessels.展开更多
The development of a possible slip line field (slf) for theoretical calculations of the deforming pressure (load) in a second pass of a lubricated cold rolling sheet mill and validation using values from an aluminium ...The development of a possible slip line field (slf) for theoretical calculations of the deforming pressure (load) in a second pass of a lubricated cold rolling sheet mill and validation using values from an aluminium sheet rolling mill was done in this work. This will be relevant in the manufacturing industries providing an easy method for determining necessary applied rolling load. Experimental rolling was carried out to observe the shear lines in the deformation field. Construction of possible slip line field model was developed adhering strictly to assumptions of rigid plastic model. Calculation of the deforming force/load was achieved using Hencky’s equation. Results showed that the load calculations for constructed slip line field using aluminium sheet rolling as an example tallied with values obtained from Tower Aluminium rolling mill. Slip line fields constructed for the second pass described adequately the rolling pressure in the cold rolling process, giving a valid solution of the exact load estimates on comparison with the industrial load values. Roll pressure along the arc of contact rose fairly linearly from the entrance to a maximum at the exit point. This work showed that slf for the first pass in a cold rolling mill cannot be used for subsequent passes;it requires construction of slfs for each pass in the cold rolling process.展开更多
针对滚动轴承传统故障诊断方法需要先验知识以及人工提取特征导致故障识别错误率高的问题,提出一种基于广义S变换(Generalized S transform,GST)和改进卷积神经网络(Convolutional Neural Network,CNN)的滚动轴承智能故障诊断方法。使用...针对滚动轴承传统故障诊断方法需要先验知识以及人工提取特征导致故障识别错误率高的问题,提出一种基于广义S变换(Generalized S transform,GST)和改进卷积神经网络(Convolutional Neural Network,CNN)的滚动轴承智能故障诊断方法。使用GST将一维振动信号转换为特征信息更加丰富的时频图,更加全面提取滚动轴承的故障特征信息。通过加入弹性斜率和高斯分布的神经元噪声,提出改进的激活函数EReLTanh(Elastic Rectified Linear Tanh,EReLTanh),并基于EReLTanh激活函数构建CNN。将得到的时频图进行压缩和归一化处理,生成时频图数据集并划分数据集。利用时频图数据集训练改进CNN,实现滚动轴承的智能故障诊断。使用自制实验平台采集不同种类滚动轴承故障数据,利用t-SNE进行全连接层特征降维可视化,结果表明:使用EReLTanh激活函数的CNN模型能够将不同故障样本的特征进行准确的分类,达到故障识别要求,同时使用该数据利用S变换、小波变换、GST并结合改进CNN和未改进CNN进行对比,提出的方法准确率得到提升。通过分析和对比实验可得出结论,利用GST和改进CNN的滚动轴承智能故障诊断方法能够在实际工程中更加简单方便地判断出故障类型及损伤程度,满足实际工程的需求。展开更多
基金supported by the National Science and Technology Major Project of China(Grant No.2011ZX05014 and 2011ZX05008-005)
文摘The ground roll and body wave usually show significant differences in arrival time, frequency content, and polarization characteristics, and conventional polarization filters that operate in either the time or frequency domain cannot consider all these elements. Therefore, we have developed a time-frequency dependent polarization filter based on the S transform to attenuate the ground roll in seismic records. Our approach adopts the complex coefficients of the S transform of the multi-component seismic data to estimate the local polarization attributes and utilizes the estimated attributes to construct the filter function. In this study, we select the S transform to design this polarization filter because its scalable window length can ensure the same number of cycles of a Fourier sinusoid, thereby rendering more precise estimation of local polarization attributes. The results of applying our approach in synthetic and real data examples demonstrate that the proposed polarization filter can effectively attenuate the ground roll and successfully preserve the body wave.
文摘To meet the demand of the pressure vessel industry, Baosteel has developed an S11306 ＋ SA516Gr70 roll-bonded clad steel plate. Comprehensive inspections of the composition, microstructure, and properties are performed to systematically evaluate the steel plate in normalized state and normalized ＋ stress relieved state. The results show the cladding interface of the Sl1306 ＋ SA516Gr70 roll-bonded clad steel plate has high shear strength, and the base metal has good mechanical properties. The performance is fully consistent with the technical requirements of the roll-bonded clad steel plate for pressure vessels.
文摘The development of a possible slip line field (slf) for theoretical calculations of the deforming pressure (load) in a second pass of a lubricated cold rolling sheet mill and validation using values from an aluminium sheet rolling mill was done in this work. This will be relevant in the manufacturing industries providing an easy method for determining necessary applied rolling load. Experimental rolling was carried out to observe the shear lines in the deformation field. Construction of possible slip line field model was developed adhering strictly to assumptions of rigid plastic model. Calculation of the deforming force/load was achieved using Hencky’s equation. Results showed that the load calculations for constructed slip line field using aluminium sheet rolling as an example tallied with values obtained from Tower Aluminium rolling mill. Slip line fields constructed for the second pass described adequately the rolling pressure in the cold rolling process, giving a valid solution of the exact load estimates on comparison with the industrial load values. Roll pressure along the arc of contact rose fairly linearly from the entrance to a maximum at the exit point. This work showed that slf for the first pass in a cold rolling mill cannot be used for subsequent passes;it requires construction of slfs for each pass in the cold rolling process.
文摘针对滚动轴承传统故障诊断方法需要先验知识以及人工提取特征导致故障识别错误率高的问题,提出一种基于广义S变换(Generalized S transform,GST)和改进卷积神经网络(Convolutional Neural Network,CNN)的滚动轴承智能故障诊断方法。使用GST将一维振动信号转换为特征信息更加丰富的时频图,更加全面提取滚动轴承的故障特征信息。通过加入弹性斜率和高斯分布的神经元噪声,提出改进的激活函数EReLTanh(Elastic Rectified Linear Tanh,EReLTanh),并基于EReLTanh激活函数构建CNN。将得到的时频图进行压缩和归一化处理,生成时频图数据集并划分数据集。利用时频图数据集训练改进CNN,实现滚动轴承的智能故障诊断。使用自制实验平台采集不同种类滚动轴承故障数据,利用t-SNE进行全连接层特征降维可视化,结果表明:使用EReLTanh激活函数的CNN模型能够将不同故障样本的特征进行准确的分类,达到故障识别要求,同时使用该数据利用S变换、小波变换、GST并结合改进CNN和未改进CNN进行对比,提出的方法准确率得到提升。通过分析和对比实验可得出结论,利用GST和改进CNN的滚动轴承智能故障诊断方法能够在实际工程中更加简单方便地判断出故障类型及损伤程度,满足实际工程的需求。
