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期刊论文 68

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关键词

位移测量 2

Chebyshev多项式 1

HeNe激光器 1

RLC网络;谐振性质;振荡特性;幅频特性 1

“彩虹”捕获 1

三塔悬索桥 1

井帮位移 1

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位移特征 1

侧流免疫检测试纸条 1

信号平稳化 1

光栅干涉仪;光学编码器;位移测量;精密测量 1

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Research on direct digital process of inductance sensor

WANG Xuan-ze, YANG Lian-gen, ZHONG Yu-ning

《机械工程前沿(英文)》 2006年 第1卷 第3期   页码 317-322 doi: 10.1007/s11465-006-0023-1

摘要: The equivalent circuit of inductance sensor is analyzed. Amplitude-displacement and phase-displacement equations are deduced for non-ideal carrier wave and inductance parameters. Simulation computation shows the corresponding digital curves. Considering that the traditional process method is an approximate one, a new method is presented to simultaneously obtain the amplitude and phase of output signal of sensor by simultaneity A/D and ellipse fit arithmetic. According to the characteristic of the amplitude-displacement and phase-displacement curves, we obtain displacement by phase and amplitude respectively when the sensor is close to the zero point position and away from other positions on the basis of the experiment. The experiment showed that this method can improve precision of measurement, and it can also work for the whole linear range of sensors even if the magnification is very high.

关键词: traditional     corresponding     phase-displacement     Amplitude-displacement     characteristic    

Lateral displacement of soft ground under vacuum pressure and surcharge load

Chin-Yee ONG, Jin-Chun CHAI

《结构与土木工程前沿(英文)》 2011年 第5卷 第2期   页码 239-248 doi: 10.1007/s11709-011-0110-1

摘要: Surcharge load (e.g. embankment fill) will induce settlement and outward lateral displacement, while vacuum pressure will induce settlement and inward lateral displacement of a ground. Ideally, combination of surcharge load and vacuum pressure can reduce or minimize the lateral displacement. Laboratory large scale model (length: 1.50 m, width: ~0.62 m, height: 0.85 m) tests and finite element analyses (FEA) were conducted to investigate the main influencing factors on lateral displacement of a soft clayey ground under the combination of vacuum pressure and surcharge load. For the conditions investigated, the results indicate that the outward lateral displacement increases with the increase of the ratio of surcharge load to vacuum pressure ( ) and the loading rate of the surcharge load ( ). Also, it is shown that for a given and condition, lateral displacement reduces with the increase of the initial undrained shear strength ( ) of the ground. To predict the lateral displacement of a ground under the combination of surcharge load and vacuum pressure, the loading conditions in terms of and , and value of the ground have to be considered.

关键词: vacuum consolidation     lateral displacement     PVD     finite element analysis     surcharge load    

Influence of advanced engineering measures on displacement and stress field of surrounding rock in tunnels

《结构与土木工程前沿(英文)》 doi: 10.1007/s11709-023-0966-x

摘要: Based on significant improvements in engineering materials, three advanced engineering measures have been proposed—super anchor cables, high-strength concrete anti-fault caverns, and grouting modification using high-strength concrete-to resist fault dislocation in the surrounding rock near tunnels crossing active strike-slip faults. Moreover, single- or multiple-joint advanced engineering measures form the local rock mass-anti-fault (LRAF) method. A numerical method was used to investigate the influence of LRAF methods on the stress and displacement fields of the surrounding rock, and the anti-fault effect was evaluated. Finally, the mechanism of action of the anchor cable was verified using a three-dimensional numerical model. The numerical results indicated that the anchor cable and grouting modification reduced the displacement gradient of the local surrounding rock near the tunnels crossing fault. Furthermore, anchor cable and grouting modifications changed the stress field of the rock mass in the modified area. The tensile stress field of the rock mass in the modified anchor cable area was converted into a compressive stress field. The stress field in the modified grouting area changed from shear stress in the fault slip direction to tensile stress in the axial tunnel direction. The anti-fault cavern resisted the dislocation displacement and reduced the maximum dislocation magnitude, displacement gradient, and shear stress. Among the three advanced engineering measures, the anchor cable was the core of the three advanced engineering measures. An anchor cable, combined with other LRAF measures, can form an artificial safety island at the cross-fault position of the rock mass to protect the tunnel. The research results provide a new supporting idea for the surrounding rock of tunnels crossing active strike-slip faults.

关键词: anti-fault effect     engineering measures     LRAF method     stress and displacement field     tunnel-crossing active faults    

Quality control based on electrode displacement and force in resistance spot welding

Chuntao JI, Lipeng DENG

《机械工程前沿(英文)》 2010年 第5卷 第4期   页码 412-417 doi: 10.1007/s11465-010-0114-x

摘要: The behaviors of electrode displacement and force during spot welding under various conditions, such as different weld currents, electrode forces, and welding times, were studied. Tests were conducted on a 170?kVA MFDC spot welder. Data were collected via a multichannel high-speed data acquisition system and were analyzed with MATLAB. Behaviors of 5182 aluminum and mild steel in spot welding were compared. Results show that nugget expansion rate does not reach zero for aluminium as it does for mild steel as nugget grew to a certain size. A linear relationship is found between the nugget size and maximum expansion that facilitates online weld quality evaluation. An electrode force peak is observed and believed relevant to the sufficient nugget size.

关键词: aluminum     electrode displacement     electrode force     nugget size     data acquisition    

Full-field dynamic strain reconstruction of an aero-engine blade from limited displacement responses

《机械工程前沿(英文)》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0731-1

摘要: Blade strain distribution and its change with time are crucial for reliability analysis and residual life evaluation in blade vibration tests. Traditional strain measurements are achieved by strain gauges (SGs) in a contact manner at discrete positions on the blades. This study proposes a method of full-field and real-time strain reconstruction of an aero-engine blade based on limited displacement responses. Limited optical measured displacement responses are utilized to reconstruct the full-field strain. The full-field strain distribution is in-time visualized. A displacement-to-strain transformation matrix is derived on the basis of the blade mode shapes in the modal coordinate. The proposed method is validated on an aero-engine blade in numerical and experimental cases. Three discrete vibrational displacement responses measured by laser triangulation sensors are used to reconstruct the full-field strain over the whole operating time. The reconstructed strain responses are compared with the results measured by SGs and numerical simulation. The high consistency between the reconstructed and measured results demonstrates the accurate strain reconstructed by the method. This paper provides a low-cost, real-time, and visualized measurement of blade full-field dynamic strain using displacement response, where the traditional SGs would fail.

关键词: aero-engine blade     displacement response     dynamic strain reconstruction     mode shape     strain gauge    

Evaluation of liquefaction-induced lateral displacement using Bayesian belief networks

Mahmood AHMAD, Xiao-Wei TANG, Jiang-Nan QIU, Feezan AHMAD

《结构与土木工程前沿(英文)》 2021年 第15卷 第1期   页码 80-98 doi: 10.1007/s11709-021-0682-3

摘要: Liquefaction-induced lateral displacement is responsible for considerable damage to engineered structures during major earthquakes. Therefore, an accurate estimation of lateral displacement in liquefaction-prone regions is an essential task for geotechnical experts for sustainable development. This paper presents a novel probabilistic framework for evaluating liquefaction-induced lateral displacement using the Bayesian belief network (BBN) approach based on an interpretive structural modeling technique. The BBN models are trained and tested using a wide-range case-history records database. The two BBN models are proposed to predict lateral displacements for free-face and sloping ground conditions. The predictive performance results of the proposed BBN models are compared with those of frequently used multiple linear regression and genetic programming models. The results reveal that the BBN models are able to learn complex relationships between lateral displacement and its influencing factors as cause–effect relationships, with reasonable precision. This study also presents a sensitivity analysis to evaluate the impacts of input factors on the lateral displacement.

关键词: Bayesian belief network     seismically induced soil liquefaction     interpretive structural modeling     lateral displacement    

Quality monitoring of resistance spot welding based on electrode displacement characteristics analysis

ZHANG Pengxian, ZHANG Hongjie, CHEN Jianhong, MA Yuezhou

《机械工程前沿(英文)》 2007年 第2卷 第3期   页码 330-335 doi: 10.1007/s11465-007-0058-y

摘要: A new method is developed to monitor joint quality based on the information collection and process in spot welding. First, twelve parameters related to weld quality are mined from electrode displacement signal on the basis of different phases of nugget formation marked by simultaneous dynamic resistance signal. Second, through correlation analysis of the parameters and taking tensile-shear strength of the spot-welded joint as evaluation target, different characteristic parameters are reasonably selected. At the same time, linear regression, nonlinear regression and radial basis function (RBF) neural network models are set up to evaluate weld quality between the selected parameters and tensile-shear strength. Finally, the validity of the proposed models is certified. Results show that all of the models can be used to monitor joint quality. For the RBF neural network model, which is more effective for monitoring weld quality than the others, the average error validated is 2.88% and the maximal error validated is under 10%.

Pore-scale simulation of water/oil displacement in a water-wet channel

Jin Zhao, Guice Yao, Dongsheng Wen

《化学科学与工程前沿(英文)》 2019年 第13卷 第4期   页码 803-814 doi: 10.1007/s11705-019-1835-y

摘要: Water/oil flow characteristics in a water-wet capillary were simulated at the pore scale to increase our understanding on immiscible flow and enhanced oil recovery. Volume of fluid method was used to capture the interface between oil and water and a pore-throat connecting structure was established to investigate the effects of viscosity, interfacial tension (IFT) and capillary number ( ). The results show that during a water displacement process, an initial continuous oil phase can be snapped off in the water-wet pore due to the capillary effect. By altering the viscosity of the displacing fluid and the IFT between the wetting and non-wetting phases, the snapped-off phenomenon can be eliminated or reduced during the displacement. A stable displacement can be obtained under high number conditions. Different displacement effects can be obtained at the same number due to its significant influence on the flow state, i.e., snapped-off flow, transient flow and stable flow, and ultralow IFT alone would not ensure a very high recovery rate due to the fingering flow occurrence. A flow chart relating flow states and the corresponding oil recovery factor is established.

关键词: VOF     pore scale     immiscible displacement     EOR     snap-off     Ca    

Assessment of bridge expansion joints using long-term displacement measurement under changing environmental

Youliang DING, Aiqun LI

《结构与土木工程前沿(英文)》 2011年 第5卷 第3期   页码 374-380 doi: 10.1007/s11709-011-0122-x

摘要: This paper addresses the problem of condition assessment of bridge expansion joints using long-term measurement data under changing environmental conditions. The effects of temperature, traffic loading and wind on the expansion joint displacements are analyzed and interpreted, which reveal that measured displacements are observed to increase with an increase in temperature and to decrease with increased traffic loading, while the correlation between displacement and wind speed is very weak. Two regression models are developed to simulate the varying displacements under the changes in temperature and traffic loadings. Based on these models, the effects of the environmental conditions are removed to obtain the normalized displacement. Statistical process control using mean value control charts is further used to detect damage to the bridge expansion joints. The results reveal that the proposed method had a good capability for detecting the damage-induced 1.0% variances of the annual changes in the expansion joint displacements.

关键词: structural health monitoring     displacement     expansion joint     temperature effect     wind effect     traffic loading     statistical process control     suspension bridge    

应用指数平滑技术预测边坡位移

沈良峰

《中国工程科学》 2007年 第9卷 第6期   页码 94-97

摘要:

应用趋势型指数平滑模型根据其观测值的数据特点(具线性趋势),选取趋势型二次指数平滑的线性 预测公式和相应at,bt的计算公式及合适的平滑系数值进行计算,预测了某市滑坡区5号监测点的位移量。预 测结果表明,该方法应用于斜坡变形位移的预测,可使预测值与实际位移值之间的误差很小。

关键词: 指数平滑     预测边坡位移     自适应过滤    

Predicting lateral displacement caused by seismic liquefaction and performing parametric sensitivity

Nima PIRHADI, Xiaowei TANG, Qing YANG, Afshin ASADI, Hazem Samih MOHAMED

《结构与土木工程前沿(英文)》 2021年 第15卷 第2期   页码 506-519 doi: 10.1007/s11709-021-0677-0

摘要: Lateral displacement due to liquefaction ( ) is the most destructive effect of earthquakes in saturated loose or semi-loose sandy soil. Among all earthquake parameters, the standardized cumulative absolute velocity ( ) exhibits the largest correlation with increasing pore water pressure and liquefaction. Furthermore, the complex effect o fine content( ) at different values has been studied and demonstrated. Nevertheless, these two contexts have not been entered into empirical and semi-empirical models to predict This study bridges this gap by adding to the data set and developing two artificial neural network (ANN) models. The first model is based on the entire range of the parameters, whereas the second model is based on the samples with values that are less than the 28% critical value. The results demonstrate the higher accuracy of the second model that is developed even with less data. Additionally, according to the uncertainties in the geotechnical and earthquake parameters, sensitivity analysis was performed via Monte Carlo simulation (MCS) using the second developed ANN model that exhibited higher accuracy. The results demonstrated the significant influence of the uncertainties of earthquake parameters on predicting

关键词: lateral spreading displacement     cumulative absolute velocity     fine content     artificial neural network     sensitivity analysis     Monte Carlo simulation    

Application of a Novel Fuzzy Clustering Method Based on Chaos Immune Evolutionary Algorithm for Edge Detection in Image Processing

《机械工程前沿(英文)》 2006年 第1卷 第1期   页码 85-89 doi: 10.1007/s11465-005-0023-6

摘要:

A novel fuzzy clustering method based on chaos immune evolutionary algorithm (CIEFCM) is presented to solve fuzzy edge detection problems in image processing. In CIEFCM, a tiny disturbance is added to a filial generation group using a chaos variable and the disturbance amplitude is adjusted step by step, which greatly improves the colony diversity of the immune evolution algorithm (IEA). The experimental results show that the method not only can correctly detect the fuzzy edge and exiguous edge but can evidently improve the searching efficiency of fuzzy clustering algorithm based on IEA.

关键词: disturbance amplitude     disturbance     diversity     generation     processing    

一种用于位移传感器的数字莫尔方法 Article

Jian WU,Ting-ting ZHOU,Bo YUAN,Li-qiang WANG

《信息与电子工程前沿(英文)》 2016年 第17卷 第9期   页码 946-953 doi: 10.1631/FITEE.1500270

摘要: 目的:在传统莫尔条纹技术的基础上,提出一种装调方便、分辨率可调节的位移测量技术。 创新点:仅使用一块光栅,利用图像处理技术生成数字莫尔条纹,从而既具有传统莫尔条纹技术的优点,又方便装调和系统分辨率设置。 方法:首先,利用面阵探测器接收光栅的放大像,并将图像信号送入计算机中。然后,将光栅像与其镜像像进行叠加产生数字莫尔条纹,并对条纹信号进行积分以得到数字莫尔曲线。最后,利用特殊设计算法估计条纹移动前后的相位差,并根据相位差计算位移量。本文根据所提出的方法构建了一套位移测量系统,对系统的稳定性、灵敏度和测量精度进行了测试。 结论:提出了一种基于数字莫尔条纹技术的位移测量方法,它既具有传统莫尔条纹技术的位移放大和误差平均的优点,又装调方便且可灵活调节分辨率。通过实验验证了该方法的可行性。

关键词: 数字莫尔条纹;位移测量;光栅    

特大跨径三塔两跨悬索桥的位移特性初探

陈策,殷海华

《中国工程科学》 2010年 第12卷 第8期   页码 79-82

摘要:

泰州大桥采用三塔两跨悬索桥方案,以泰州大桥工程为例,分析了三塔悬索桥与双塔悬索桥位移特征的不同点,并研究分析了塔的刚度、高度、主梁高度、矢跨比变化、边中跨比变化对三塔悬索桥位移特征的影响。

关键词: 三塔悬索桥     泰州大桥     位移特征     影响参数    

Controlling nested wrinkle morphology through the boundary effect on narrow-band thin films

Hanyang XU, Tielin SHI, Guanglan LIAO, Qi XIA

《机械工程前沿(英文)》 2019年 第14卷 第2期   页码 235-240 doi: 10.1007/s11465-017-0458-6

摘要: We describe the formation of nested wrinkles created by the thermal mismatch between a narrow-band thin film and a compliant substrate. When a film is described as “narrow-band”, it literally means that the film band width is much shorter than its length; more precisely, it means that the width is comparable with the wavelength of the wrinkles. A silicon mask was used during film sputtering to create narrow-band films on poly (dimethylsiloxane) substrate, thus creating regular boundaries to steer local stresses and control wrinkle morphology. Disordered nano-scale wrinkles were found nested within highly ordered micro-scale sinusoidal wrinkles. The formation of nested wrinkles was explained through the amplitude and wavelength saturation of nano-scale wrinkles. The disordered morphology of nano-scale wrinkles and the highly ordered morphology of micro-scale wrinkles were explained by using the boundary effect.

关键词: nested and hierarchical wrinkles     morphology     amplitude saturation     boundary effect    

标题 作者 时间 类型 操作

Research on direct digital process of inductance sensor

WANG Xuan-ze, YANG Lian-gen, ZHONG Yu-ning

期刊论文

Lateral displacement of soft ground under vacuum pressure and surcharge load

Chin-Yee ONG, Jin-Chun CHAI

期刊论文

Influence of advanced engineering measures on displacement and stress field of surrounding rock in tunnels

期刊论文

Quality control based on electrode displacement and force in resistance spot welding

Chuntao JI, Lipeng DENG

期刊论文

Full-field dynamic strain reconstruction of an aero-engine blade from limited displacement responses

期刊论文

Evaluation of liquefaction-induced lateral displacement using Bayesian belief networks

Mahmood AHMAD, Xiao-Wei TANG, Jiang-Nan QIU, Feezan AHMAD

期刊论文

Quality monitoring of resistance spot welding based on electrode displacement characteristics analysis

ZHANG Pengxian, ZHANG Hongjie, CHEN Jianhong, MA Yuezhou

期刊论文

Pore-scale simulation of water/oil displacement in a water-wet channel

Jin Zhao, Guice Yao, Dongsheng Wen

期刊论文

Assessment of bridge expansion joints using long-term displacement measurement under changing environmental

Youliang DING, Aiqun LI

期刊论文

应用指数平滑技术预测边坡位移

沈良峰

期刊论文

Predicting lateral displacement caused by seismic liquefaction and performing parametric sensitivity

Nima PIRHADI, Xiaowei TANG, Qing YANG, Afshin ASADI, Hazem Samih MOHAMED

期刊论文

Application of a Novel Fuzzy Clustering Method Based on Chaos Immune Evolutionary Algorithm for Edge Detection in Image Processing

期刊论文

一种用于位移传感器的数字莫尔方法

Jian WU,Ting-ting ZHOU,Bo YUAN,Li-qiang WANG

期刊论文

特大跨径三塔两跨悬索桥的位移特性初探

陈策,殷海华

期刊论文

Controlling nested wrinkle morphology through the boundary effect on narrow-band thin films

Hanyang XU, Tielin SHI, Guanglan LIAO, Qi XIA

期刊论文