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Application and evaluation of layering shear method in LADCP data processing
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作者 Zijian Cui Chujin Liang +2 位作者 Binbin Guo Feilong Lin Yong Mu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第12期9-21,共13页
The current velocity observation of LADCP(Lowered Acoustic Doppler Current Profiler)has the advantages of a large vertical range of observation and high operability compared with traditional current measurement method... The current velocity observation of LADCP(Lowered Acoustic Doppler Current Profiler)has the advantages of a large vertical range of observation and high operability compared with traditional current measurement methods,and is being widely used in the field of ocean observation.Shear and inverse methods are now commonly used by the international marine community to process LADCP data and calculate ocean current profiles.The two methods have their advantages and shortcomings.The shear method calculates the value of current shear more accurately,while the accuracy in an absolute value of the current is lower.The inverse method calculates the absolute value of the current velocity more accurately,but the current shear is less accurate.Based on the shear method,this paper proposes a layering shear method to calculate the current velocity profile by“layering averaging”,and proposes corresponding current calculation methods according to the different types of problems in several field observation data from the western Pacific,forming an independent LADCP data processing system.The comparison results have shown that the layering shear method can achieve the same effect as the inverse method in the calculation of the absolute value of current velocity,while retaining the advantages of the shear method in the calculation of a value of the current shear. 展开更多
关键词 LADCP data processing layering shear method Western Pacific
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Mechanical mechanism analysis of tension type anchor based on shear displacement method 被引量:18
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作者 肖淑君 陈昌富 《Journal of Central South University of Technology》 EI 2008年第1期106-111,共6页
Based on the fact that the shear stress along anchorage segment is neither linearly nor uniformly distributed, the load transfer mechanism of the tension type anchor was studied and the mechanical characteristic of an... Based on the fact that the shear stress along anchorage segment is neither linearly nor uniformly distributed, the load transfer mechanism of the tension type anchor was studied and the mechanical characteristic of anchorage segment was analyzed. Shear stress?strain relationship of soil surrounding anchorage body was simplified into three-folding-lines model consisting of elastic phase, elasto-plastic phase and residual phase considering its softening characteristic. Meanwhile, shear displacement method that has been extensively used in the analysis of pile foundation was introduced. Based on elasto-plastic theory, the distributions of displacement, shear stress and axial force along the anchorage segment of tension type anchor were obtained, and the formula for calculating the elastic limit load was also developed accordingly. Finally, an example was given to discuss the variation of stress and displacement in the anchorage segment with the loads exerted on the anchor, and a program was worked out to calculate the anchor maximum bearing capacity. The influence of some parameters on the anchor bearing capacity was discussed, and effective anchorage length was obtained simultaneously. The results show that the shear stress first increases and then decreases and finally trends to the residual strength with increase of distance from bottom of the anchorage body, the displacement increases all the time with the increase of distance from bottom of the anchorage body, and the increase of velocity gradually becomes greater. 展开更多
关键词 ANCHOR anchorage segment tension type ELASTO-PLASTICITY mechanical analysis shear displacement method residual strength
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Mesomechanics Finite-element Method for Determining the Shear Strength of Mudded Intercalation Materials 被引量:2
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作者 胡启军 SHI Rendan +3 位作者 YANG Xiaoqiang CAI Qijie HE Tianjun HE Leping 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2017年第2期289-291,共3页
A new method regarding mesomechanics finite-element research is proposed to predict the peak shear strength of mudded intercalation materials on a mesoscopic scale. Based on geometric and mechanical parameters, along ... A new method regarding mesomechanics finite-element research is proposed to predict the peak shear strength of mudded intercalation materials on a mesoscopic scale. Based on geometric and mechanical parameters, along with the strain failure criteria obtained by sample's deformation characteristics, uniaxial compression tests on the sample were simulated through a finite-element model, which yielded values consistent with the data from the laboratory uniaxial compression tests, implying that the method is reasonable. Based on this model, a shear test was performed to calculate the peak shear strength of the mudded intercalation, consistent with values reported in the literature, thereby providing a new approach for investigating the mechanical properties of mudded intercalation materials. 展开更多
关键词 mudded intercalation mesomechanics finite-element method mesoscale structure shear strength
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Settlement calculation for long-short composite piled raft foundation 被引量:4
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作者 赵明华 张玲 杨明辉 《Journal of Central South University of Technology》 EI 2006年第6期749-754,共6页
The mechanism of long-short composite piled raft foundation was discussed. Assuming the relationship between shear stress and shear strain of the surrounding soil was elasto-plastic, shear displacement method was empl... The mechanism of long-short composite piled raft foundation was discussed. Assuming the relationship between shear stress and shear strain of the surrounding soil was elasto-plastic, shear displacement method was employed to establish the different explicit relational equations between the load and the displacement at the top of pile in either elastic or elasto-plastic period. Then Mylonakis & Gazetas model was introduced to simulate the interaction between two piles or between piles and soil. Considering the effect of cushion, the flexible coefficients of interaction were provided, With the addition of a relevant program, the settlement calculation for long-short composite piled raft foundation was developed which could be used to account for the interaction of piles, soil and cushion. Finally, the calculation method was used to analyze an engineering example. The calculated value of settlement is 10.2 ram, which is close to the observed value 8.8 mm. 展开更多
关键词 long-short composite oiled raft foundation shear displacement method SETTLEMENT Mylonakis Gazetas model
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Fluid–solid coupling analysis of rock pillar stability for concealed karst cave ahead of a roadway based on catastrophic theory 被引量:10
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作者 Zhao Yanlin Peng Qingyang +2 位作者 Wan Wen Wang Weijun Chen Bin 《International Journal of Mining Science and Technology》 SCIE EI 2014年第6期737-745,共9页
In order to study the mechanism of water inrush from a concealed, confined karst cave, we established a fluid–solid coupling model of water inrush from a concealed karst cave ahead of a roadway and a strength reducti... In order to study the mechanism of water inrush from a concealed, confined karst cave, we established a fluid–solid coupling model of water inrush from a concealed karst cave ahead of a roadway and a strength reduction method in a rock pillar for preventing water inrush based on catastrophic theory. Fluid–solid coupling effects and safety margins in a rock pillar were studied. Analysis shows that rock pillar instability, exerted by disturbance stress and seepage stress, is the process of rock pillar catastrophic destabilization induced by nonlinear extension of plastic zones in the rock pillar. Seepage flow emerges in the rock pillar for preventing water inrush, accompanied by mechanical instability of the rock pillar. Taking the accident of a confined karst cave water-inrush of Qiyi Mine as an example, by studying the safety factor of the rock pillar and the relationship between karst cave water pressure and thickness of the rock pillar,it is proposed that rock pillar thickness with a safety factor equal to 1.5 is regarded as the calculated safety thickness of the rock pillar, which should be equal to the sum of the blasthole depth, blasting disturbance depth and the calculated safety thickness of the rock pillar. The cause of the karst water inrush at Qiyi Mine is that the rock pillar was so small that it did not possess a safety margin. Combining fluid–solid coupling theory, catastrophic theory and strength reduction method to study the nonlinear mechanical response of complicated rock engineering, new avenues for quantitative analysis of rock engineering stability evaluation should be forthcoming. 展开更多
关键词 Rock mechanics Catastrophic theory Shear strength reduction method Karst water inrush Safety factor
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Numerical Analysis of the Stability of Embankment Slope Reinforced with Piles 被引量:1
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作者 崔溦 张志耕 闫澍旺 《Transactions of Tianjin University》 EI CAS 2007年第2期126-130,共5页
The effects of stabilizing piles on the stability of an embankment slope are analyzed by numerical simulation. The shear strength reduction method is used for the analysis, and the soil - pile interaction is simulated... The effects of stabilizing piles on the stability of an embankment slope are analyzed by numerical simulation. The shear strength reduction method is used for the analysis, and the soil - pile interaction is simulated with zero-thickness elasto-plastic interface elements. Effects of pile spacing and pile position on the safety factor of slope and the behavior of piles under these conditions are given. The numerical analysis indicates that the positions of the pile have significant influence on the stability of the slope, and the pile needs to be installed in the middle of the slope for maximum safety factors. In the end, the soil arching effect closely associated with the space between stabilizing piles is analyzed. The results are helpful for design and construction of stabilizing piles. 展开更多
关键词 stabilizing piles embankment slope shear strength reduction method interface element numerical simulation
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Analysis on Shear Deformation for High Manganese Austenite Steel during Hot Asymmetrical Rolling Process Using Finite Element Method 被引量:4
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作者 Feng-li SUI Xin WANG +2 位作者 Jun ZHAO Biao MA Chang-sheng LI 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2015年第11期990-995,共6页
Based on the rigid-plastic finite element method(FEM), the shear stress field of deformation region for high manganese austenite steel during hot asymmetrical rolling process was analyzed. The influences of rolling ... Based on the rigid-plastic finite element method(FEM), the shear stress field of deformation region for high manganese austenite steel during hot asymmetrical rolling process was analyzed. The influences of rolling parameters, such as the velocity ratio of upper to lower rolls, the initial temperature of workpiece and the reduction rate, on the shear deformation of three nodes in the upper, center and lower layers were discussed. As the rolling parameters change, distinct shear deformation appears in the upper and lower layers, but the shear deformation in the center layer appears only when the velocity ratio is more than 1.00, and the absolute value of the shear stress in this layer is changed with rolling parameters. A mathematical model which reflected the change of the maximal absolute shear stress for the center layer was established, by which the maximal absolute shear stress for the center layer can be easily calculated and the appropriate rolling technology can be designed. 展开更多
关键词 high manganese austenite steel hot asymmetrical rolling shear deformation finite element method
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A numerical study of violent sloshing problems with modified MPS method 被引量:6
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作者 Debadatta Jena Kishore Chandra Biswal 《Journal of Hydrodynamics》 SCIE EI CSCD 2017年第4期659-667,共9页
A numerical study on violent liquid sloshing phenomenon in a partially filled rectangular container is carried out by using moving particle semi-implicit(MPS) method. The present study deals with the implementation ... A numerical study on violent liquid sloshing phenomenon in a partially filled rectangular container is carried out by using moving particle semi-implicit(MPS) method. The present study deals with the implementation of five modifications all together over the original MPS method. The modifications include improved source terms for pressure Poisson equation, special approximation technique for the representation of gradient differential operator, collective action of mixed free surface particle identification boundary conditions, effecting Neumann boundary condition on solving the PPE and fixing judiciously the parting distance among particles to prevent collision. The suitability of the kernel function used in the original MPS method along with these five modifications is investigated for violent sloshing problems. The present model ensures a good agreement between numerical results with the existing experimental observations. The model is successfully applied to a partially filled tank undergoing horizontal sinusoidal excitation to compute the sloshing wave amplitudes and pressure on tank walls. The assessment of dynamic behaviour manifested in terms of base shear, overturning moment and impact pressure load exerted on tank ceiling induced by violent sloshing motion using MPS method is not reported in the open literature and has been efficiently carried out in the present study. 展开更多
关键词 Sloshing particle method impact pressure base shear overturning moment
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An erosion model for the discrete element method 被引量:6
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作者 Yongzhi Zhao Huacling Ma +1 位作者 Lei Xu Jinyang Zheng 《Particuology》 SCIE EI CAS CSCD 2017年第5期81-88,共8页
A shear impact energy model (SIEM) of erosion suitable for both dilute and dense particle flows is pro- posed based on the shear impact energy of particles in discrete element method (DEM) simulations. A number of... A shear impact energy model (SIEM) of erosion suitable for both dilute and dense particle flows is pro- posed based on the shear impact energy of particles in discrete element method (DEM) simulations. A number of DEM simulations are performed to determine the relationship between the shear impact energy predicted by the DEM model and the theoretical erosion energy. Simulation results show that nearly one-quarter of the shear impact energy will be converted to erosion during an impingement. According to the ratio of the shear impact energy to the erosion energy, it is feasible to predict erosion from the shear impact energy, which can be accumulated at each time step for each impingement during the DEM simulation. The total erosion of the target surface can be obtained by summing the volume of material removed from each impingement. The proposed erosion model is validated against experiment and results show that the SIEM combined with DEM accurately predicts abrasive erosions. 展开更多
关键词 Discrete element method Erosion Wear Impact angle Shear impact energy mode
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Discrete element method study of shear-driven granular segregation in a slowly rotating horizontal drum 被引量:4
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作者 Ram Chand Sithi V. Muniandy +1 位作者 Chiow San Wong Jasbir Singh 《Particuology》 SCIE EI CAS CSCD 2017年第3期89-94,共6页
Segregation and mixing of granular materials are complex processes and are not fully understood. Motivated by industrial need, we performed a simulation using the discrete element method to study size segregation of a... Segregation and mixing of granular materials are complex processes and are not fully understood. Motivated by industrial need, we performed a simulation using the discrete element method to study size segregation of a binary mixture of granular particles in a horizontal rotating drum. Particles of two dif- ferent sizes were poured into the drum until it was 50% full. Shear-driven segregation was induced by rotating the side-plates of the drum in the opposite direction to that of the cylindrical wall. We found that radial segregation diminished in these systems but did not completely vanish. In an ordinary rotating drum, a radial core of smaller particles is formed in the center of the drum, surrounded by larger revolving particles. In our system, however, the smaller particles were found to migrate toward the side-plates. The shear from anti-spinning side-plates reduces the voidage and increases the bulk density. As such, smaller particles in the mixer tend to move to denser regions. We varied the shear by changing the coefficient of friction on the side-plates to study the influence of shear rate on this migration. We also compared the extent of radial segregation with stationary side-plates and with side-plates moving in different angular directions. 展开更多
关键词 Granular flow Discrete element method Segregation Side-wall shear Rotating drum Mixing
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Macro- and micromechanical evaluation of cyclic simple shear test by discrete element method 被引量:1
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作者 Mozhgan Asadzadeh Abbas Soroush 《Particuology》 SCIE EI CAS CSCD 2017年第2期129-139,共11页
Direct simple shear tests are considered to be simple laboratory tests that are capable of imposing a cyclic loading that is analogous to that induced by earthquakes. A realistic evaluation of the test results demands... Direct simple shear tests are considered to be simple laboratory tests that are capable of imposing a cyclic loading that is analogous to that induced by earthquakes. A realistic evaluation of the test results demands a profound micromechanical investigation of specimens. Three-dimensional discrete element method models of a stacked-ring simple shear test were constructed, in which monotonic and cyclic loadings were applied under constant-volume conditions, and good agreement between the monotonic and cyclic macromechanical behaviors was noted. Micromechanical properties of specimens that were subjected to a cyclic loading are discussed in terms of lateral and intermediate principal stress development, fabric anisotropy, and principal stress rotation. The stress and strain states inside the specimen were investigated and it was shown that despite the uniform stress distribution inside the specimen, the volumetric strain distributes non-uniformly during loading and the non-uniformity grows with cycling, which leads to localized zones of dilative and contractive behavior. 展开更多
关键词 Discrete element method Direct shear test Simple shear test Cyclic loading
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Investigation on method for measuring dynamic shear modulus of underwater acoustic structure materials 被引量:1
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作者 LI Shui TANG Haiqing MIAO Rongxing (Hangzhou Applied Acoustic Institute Fuyang Zhejiang 311400) 《Chinese Journal of Acoustics》 1999年第2期121-127,共7页
A new method is described to measure the dynamic shear modulus of underwater acoustic structure materials in a small anechoic water tank by using a broadband parametric source, a precise coordinate installation and te... A new method is described to measure the dynamic shear modulus of underwater acoustic structure materials in a small anechoic water tank by using a broadband parametric source, a precise coordinate installation and techniques of signal processing in the frequency range of 20 kHz - 100 kHz. The typical size of material samples is 500×500 mm2. Basic principles, experiment installation and measured results are also presented 展开更多
关键词 Investigation on method for measuring dynamic shear modulus of underwater acoustic structure materials
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Influence of reaction piles on test pile response in a static load test 被引量:2
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作者 Qian-qing ZHANG Shu-cai LI Zhong-miao ZHANG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2013年第3期198-205,共8页
This work presents a new analytical method to analyze the influence of reaction piles on the test pile response in a static load test.In our method,the interactive effect between soil and pile is simulated using indep... This work presents a new analytical method to analyze the influence of reaction piles on the test pile response in a static load test.In our method,the interactive effect between soil and pile is simulated using independent springs and the shear displacement method is adopted to analyze the influence of reaction piles on test pile response.Moreover,the influence of the sheltering effect between reaction piles and test pile on the test pile response is taken into account.Two cases are analyzed to verify the rationality and efficiency of the present method.This method can be easily extended to a nonlinear response of an influenced test pile embedded in a multilayered soil,and the validity is also demonstrated using centrifuge model tests and a computer program presented in the literature.The present analyses indicate that the proposed method will lead to an underestimation of the test pile settlement in a static load test if the influence of the presence of reaction piles on the test pile response is neglected. 展开更多
关键词 Test pile Reaction pile Shear displacement method Sheltering effect Multilayered soil
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