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Rainfall-triggered waste dump instability analysis based on surface 3D deformation in physical model test
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作者 LI Hanlin JIN Xiaoguang +2 位作者 HE Jie XUE Yunchuan YANG Zhongping 《Journal of Mountain Science》 SCIE CSCD 2024年第5期1549-1563,共15页
Landslide is the second largest natural disaster after earthquake. It is of significance to study the evolution laws and failure mechanism of landslides based on its surface 3D deformation information. Based on the ra... Landslide is the second largest natural disaster after earthquake. It is of significance to study the evolution laws and failure mechanism of landslides based on its surface 3D deformation information. Based on the rainfall-triggered waste dump instability model test, we studied the failure mechanisms of the waste dump by integrating surface deformation and internal slope stress and proposed novel parameters for identifying landslide stability. We developed a noncontact measurement device, which can obtain millimeter-level 3D deformation data for surface scene in physical model test;Then we developed the similar materials and established a test model for a waste dump. Based on the failure characteristics of slope surface, internal stress of slope body and displacement contours during the whole process, we divided the slope instability process in model test into four stages: rainfall infiltration and surface erosion, shallow sliding, deep sliding, and overall instability. Based on the obtained surface deformation data, we calculated the volume change during slope instability process and compared it with the point displacement on slope surface. The results showed that the volume change can not only reflect the slow-ultra acceleration process of slope failure, but also fully reflect the above four stages and reduce the fluctuations caused by random factors. Finally, this paper proposed two stability identification parameters: the volume change rate above the slip surface and the relative velocity of volume change rate. According to the calculation of these two parameters in model test, they can be used for study the deformation and failure mechanism of slope stability. 展开更多
关键词 Waste dump stability Physical model test Surface 3D deformation Stability identification
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Research on casing deformation prevention technology based on cementing slurry system optimization
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作者 Yan Yan Meng Cai +3 位作者 Wen-Hai Ma Xiao-Chuan Zhang Li-Hong Han Yong-Hong Liu 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期1231-1240,共10页
The casing deformation prevention technology based on the optimization of cement slurry is proposed to reduce the casing deformation of shale oil and gas wells during hydraulic fracturing. In this paper, the fracture ... The casing deformation prevention technology based on the optimization of cement slurry is proposed to reduce the casing deformation of shale oil and gas wells during hydraulic fracturing. In this paper, the fracture mechanism of hollow particles in cement sheath was firstly analyzed by discrete element method, and the effect of hollow particles in cement on casing deformation was investigated by laboratory experiment method. Finally, field test was carried out to verify the improvement effect of the casing deformation based on cement slurry modification. The results show that the formation displacement can be absorbed effectively by hollow particles inside the cement transferring the excessive deformation away from casing. The particles in the uncemented state provide deformation space during formation slipping. The casing with diameter of 139.7 mm could be passed through by bridge plug with the diameter of 99 mm when the mass ratio of particle/cement reaches 1:4. According to the field test feedback, the method based on optimization of cement slurry can effectively reduce the risk of casing deformation, and the recommended range of hollow microbeads content in the cement slurry is between 15% and 25%. 展开更多
关键词 Cement slurry Hollow ceramsite Casing deformation Formation slip Field test
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Analysis of rotor eddy current loss and thermal deformation of magnetic liquid double suspension bearing
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作者 LIU Hongmei YANG Guang +3 位作者 SUN Yanan SUN Jian WANG Zhe ZHAO Jianhua 《High Technology Letters》 EI CAS 2024年第3期322-332,共11页
Magnetic-liquid double suspension bearing(MLDSB)is a new type of suspension bearing based on electromagnetic suspension and supplemented by hydrostatic supporting.Without affecting the electromagnetic suspension force... Magnetic-liquid double suspension bearing(MLDSB)is a new type of suspension bearing based on electromagnetic suspension and supplemented by hydrostatic supporting.Without affecting the electromagnetic suspension force,the hydrostatic supporting effect is increased,and the real-time coupling of magnetic and liquid supporting can be realized.However,due to the high rotation speed,the rotor part produces eddy current loss,resulting in a large temperature rise and large ther-mal deformation,which makes the oil film thickness deviate from the initial design.The support and bearing characteristics are seriously affected.Therefore,this paper intends to explore the internal effects of eddy current loss of the rotor on the temperature rise and thermal deformation of MLDSB.Firstly,the 2D magnetic flow coupling mathematical model of MLDSB is established,and the eddy current loss distribution characteristics of the rotor are numerically simulated by Maxwell software.Secondly,the internal influence of mapping relationship of structural operating parameters such as input current,coil turns and rotor speed on rotor eddy current loss is revealed,and the changing trend of rotor eddy current loss under different design parameters is explored.Thirdly,the eddy cur-rent loss is loaded into the heat transfer finite element calculation model as a heat source,and the temperature rise of the rotor and its thermal deformation are simulated and analyzed,and the influ-ence of eddy current loss on rotor temperature rise and thermal deformation is revealed.Finally,the pressure-flow curve and the distribution law of the internal flow field are tested by the particle image velocimetry(PIV)system.The results show that eddy current loss increases linearly with the in-crease of coil current,coil turns and rotor speed.The effect of rotational speed on eddy current loss is much higher than that of coil current and coil turns.The maximum temperature rise,minimum temperature rise and maximum thermal deformation of the rotor increase with the increase of eddy current loss.The test results of flow-pressure and internal trace curves are basically consistent with the theoretical simulation,which effectively verifies the correctness of the theoretical simulation.The research results can provide theoretical basis for the design and safe and stable operation of magnetic fluid double suspension bearings. 展开更多
关键词 magnetic-liquid double suspension bearing(MLDSB) oil film thickness cur-rent loss thermal deformation particle image velocimetry(PIV)test
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Poroelastodynamic responses and elastic moduli of a transversely isotropic porous cylinder under forced deformation test
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作者 Chao Liu Dung T.Phan 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第7期793-800,共8页
Existing transversely isotropic poroelastodynamics solutions are limited to infinite domains and without experimental validation. Furthermore, there is a lack of analytical simulations for the elastic moduli dispersio... Existing transversely isotropic poroelastodynamics solutions are limited to infinite domains and without experimental validation. Furthermore, there is a lack of analytical simulations for the elastic moduli dispersion of fluid-saturated porous cylinders. To address these three limitations and investigate the mechanisms of moduli dispersion, we present the analytical solutions of the poromechanical responses and the elastic moduli dispersion of a transversely isotropic, fluid-saturated, finite porous cylinder subjected to a forced deformation test. Through an example, we demonstrate the effects of loading frequency, boundary conditions, and material's anisotropy, dimension, and permeability on the responses of pore pressure,force, displacement, and dynamic elastic moduli of the cylinder. The specimen's responses are significantly influenced by the frequency of the applied load, resulting in a drained state at low frequencies and an undrained state at high frequencies. At high frequencies, the sample behaves identically for an open or a closed lateral boundary, and permeability has insignificant effects. The dynamic elastic moduli are mainly controlled by the loading frequency and the ratio of the sample's radius to its height. Lastly,we show excellent matches between the newly derived analytical solution and laboratory measurements on one clay and two shale samples from Mont Terri. 展开更多
关键词 Poroelastodynamics Dynamic moduli Transversely isotropic Porous cylinder Forced deformation test
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Assessment of cyclic deformation and critical stress amplitude of jointed rocks via cyclic triaxial testing
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作者 Waranga Habaraduwa Peellage Behzad Fatahi Haleh Rasekh 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第6期1370-1390,共21页
Jointed rock specimens with a natural replicated joint surface oriented at a mean dip angle of 60were prepared,and a series of cyclic triaxial tests was performed at different confining pressures and cyclic deviatoric... Jointed rock specimens with a natural replicated joint surface oriented at a mean dip angle of 60were prepared,and a series of cyclic triaxial tests was performed at different confining pressures and cyclic deviatoric stress amplitudes.The samples were subjected to 10,000 loading-unloading cycles with a frequency of 8 Hz.At each level of confining pressure,the applied cyclic deviatoric stress amplitude was increased incrementally until excessive deformation of the jointed rock specimen was observed.Analysis of the test results indicated that there existed a critical cyclic deviatoric stress amplitude(i.e.critical dynamic deviatoric stress)beyond which the jointed rock specimens yielded.The measured critical dynamic deviatoric stress was less than the corresponding static deviatoric stress.At cyclic deviatoric stress amplitudes less than the critical dynamic deviatoric stress,minor cumulative residual axial strains were observed,resulting in hysteretic damping.However,for cyclic deviatoric stresses beyond the critical dynamic deviatoric stress,the plastic strains increased promptly,and the resilient moduli degraded rapidly during the initial loading cycles.Cyclic triaxial test results showed that at higher confining pressures,the ultimate residual axial strain attained by the jointed rock specimen decreased,the steadystate dissipated energy density and steady-state damping ratio per load cycle decreased,while steadystate resilient moduli increased. 展开更多
关键词 Cyclic triaxial test Jointed rock Joint surface Confining pressure Cyclic deviatoric stress amplitude FAILURE Residual deformation Dissipated energy
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Influence of deformation on the corrosion behavior of LZ91 Mg-Li alloy 被引量:3
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作者 Xueqin Liu Xuejian Wang +3 位作者 Enyu Guo Zongning Chen Huijun Kang Tongmin Wang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第1期72-81,共10页
The effect of rolling and forging on the microstructure and corrosion behavior of LZ91 alloy was investigated using an electron probe micro-analyzer,immersion and electrochemical tests.Results showed that the area fra... The effect of rolling and forging on the microstructure and corrosion behavior of LZ91 alloy was investigated using an electron probe micro-analyzer,immersion and electrochemical tests.Results showed that the area fraction of theβ-Li phase remained unchanged,and the grain size of theβ-Li phase decreased after forging.The as-rolled forged alloy(FR-LZ91)exhibited the highest area fraction of theβ-Li phase and the longest grains.The corrosion resistance of the forged LZ91 alloy increased due to grain refinement that prevented further corrosion during the immersion test.Among the experimental alloys,FR-LZ91 showed the highest resistance of corrosion film and charge transfer resistance values due to its protective film caused by the high area fraction of theβ-Li phase. 展开更多
关键词 magnesium lithium alloy deformation electrochemical test corrosion behavior
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Anchorage performance of large-diameter FRP bolts and their application in large deformation roadway 被引量:2
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作者 Jun Han Zuoqing Bi +2 位作者 Bing Liang Chen Cao Shuangwen Ma 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第8期1037-1043,共7页
In underground coal mines, fibre reinforced polymer(FRP) bolt is ideal for mined rib reinforcements as it can prevent gas explosions caused by shearer frictional spark. With increasing mining depth, small diameter FRP... In underground coal mines, fibre reinforced polymer(FRP) bolt is ideal for mined rib reinforcements as it can prevent gas explosions caused by shearer frictional spark. With increasing mining depth, small diameter FRP bolts used in shallow underground mining cannot fulfil the rib support requirements. Under the engineering background of deep underground shortwall mining in Wudong coal mine, this paper systematically studies Φ27 mm FRP bolt support for large deformation coal rib. Specimens with a fan-shaped cross-section were used to enable the tensile testing of the bolt rod, the measured average tensile strength of the studied FRP bolt was(486.1 ± 9.6) MPa with a maximum elongation of 5.7%±0.6%.The shear strength of the bolt was measured as approximately 258 MPa using a self-made double shear testing apparatus. Based on the equivalent radial stiffness principle, a laboratory short encapsulation pullout test(SEPT) method for rib bolting has been developed undertaken consideration of the mechanical properties of the coal seam. Results showed that the average peak anchorage forces of the Φ27 mm FRP bolt and Φ20 mm steel rebar bolt were 108.4 and 66.4 k N, respectively, which were agreed with the theoretical calculations and field measurements. Based on theoretical analysis of the loading states of the bolt under site conditions, bolting method of full-length resin grouting was adopted to offset the weaknesses of the FRP bolt. Numerical method was employed to compare the bolting effect using Φ27 mm FRP bolts and steel rebar bolts. Large diameter FRP bolting was determined as the optimum rib support scheme to increase the productivity of the coal mine and to enhance the ground control capability for+425 level mining roadways. This study provides the laboratory testing design and theoretical prediction of large diameter FRP bolts used for rib support in large deformation roadways. 展开更多
关键词 FRP bolt Laboratory SEPT Tensile strength Double shear testing Mined rib support Large deformation roadway
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Test Investigation on Liquefied Deformation Structure in Saturated Lime-Mud Composites Triggered by Strong Earthquakes 被引量:10
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作者 TIAN Hongshui ZHANG Shenhe ZHANG Aishe 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2016年第6期2008-2021,共14页
Three identical model boxes were made from transparent plexiglass and angle iron. Using the method of sinking water and according to the sedimentary rhythm of saturated calcium carbonate (lime-mud) intercalated with... Three identical model boxes were made from transparent plexiglass and angle iron. Using the method of sinking water and according to the sedimentary rhythm of saturated calcium carbonate (lime-mud) intercalated with cohesive soil, calcites with particle sizes diameters of ≤ 5 μm, 10–15 μm and 23–30 μm as well as cohesive soil were sunk alternatively in water of three boxes to build three test models, each of which has a specific size of calcite. Pore water pressure gauges were buried in lime-mud layers at different depths in each model, and connected with a computer system to collect pore water pressures. By means of soil tests, physical property parameters and plasticity indices (Ip) were obtained for various grain-sized saturated lime-muds. The lime-muds with Ip ranging from 6.3 to 8.5 (lower than 10) are similar to liquid saturated silt in the physical nature, indicating that saturated silt can be liquefied once induced by a strong earthquake. One model cart was pushed quickly along the length direction of the model so that its rigid wheels collided violently with the stone stair, thus generating an artificial earthquake with seismic wave magnitude greater than VI degree. When unidirectional cyclic seismic load of horizontal compression-tension-shear was imposed on the soil layers in the model, enough great pore water pressure has been accumulated within pores of lime-mud, resulting in liquefaction of lime-mud layers. Meanwhile, micro-fractures formed in each soil layer provided channels for liquefaction dewatering, resulting in formation of macroscopic liquefaction deformation, such as liquefied lime-mud volcanoes, liquefied diapir structures, vein-like liquefied structures and liquefied curls, etc. Splendid liquefied lime-mud eruption lasted for two to three hours, which is similar to the sand volcano eruption induced by strong earthquake. However, under the same artificial seismic conditions, development of macroscopic liquefied structures in three experimental models varied in shape, depth and quantity, indicating that excess pore water pressure ratios at initial liquefaction stage and complete liquefaction varied with depth. With size increasing of calcite particle in lime-mud, liquefied depth and deformation extent increase accordingly. The simulation test verifies for the first time that strong earthquakes may cause violent liquefaction of saturated lime-mud composed of micron-size calcite particles, uncovering the puzzled issue whether seafloor lime-mud can be liquefied under strong earthquake. This study not only provides the latest simulation data for explaining the earthquake-induced liquefied deformations of saturated lime-mud and seismic sedimentary events, but also is of great significance for analysis of foundation stability in marine engineering built on the soft calcium carbonate layers in neritic environment. 展开更多
关键词 simulation test saturated lime-mud liquefaction-induced deformation lime-mud volcano EARTHQUAKE
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Considerations of rock dilation on modeling failure and deformation of hard rocks-a case study of the mine-by test tunnel in Canada 被引量:9
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作者 Xingguang Zhao Meifeng Cai MCai 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE 2010年第4期338-349,共12页
For the compressive stress-induced failure of tunnels at depth, rock fracturing process is often closely associated with the generation of surface parallel fractures in the initial stage, and shear failure is likely t... For the compressive stress-induced failure of tunnels at depth, rock fracturing process is often closely associated with the generation of surface parallel fractures in the initial stage, and shear failure is likely to occur in the final process during the formation of shear bands, breakouts or V-shaped notches close to the excavation boundaries. However, the perfectly elastoplastic, strain-softening and elasto-brittle-plastic models cannot reasonably describe the brittle failure of hard rock tunnels under high in-situ stress conditions. These approaches often underestimate the depth of failure and overestimate the lateral extent of failure near the excavation. Based on a practical case of the mine-by test tunnel at an underground research laboratory (URL) in Canada, the influence of rock mass dilation on the depth and extent of failure and deformation is investigated using a calibrated cohesion weakening and frictional strengthening (CWFS) model. It can be found that, when modeling brittle failure of rock masses, the calibrated CWFS model with a constant dilation angle can capture the depth and extent of stress-induced brittle failure in hard rocks at a low confinement if the stress path is correctly represented, as demonstrated by the failure shape observed in the tunnel. However, using a constant dilation angle cannot simulate the nonlinear deformation behavior near the excavation boundary accurately because the dependence of rock mass dilation on confinement and plastic shear strain is not considered. It is illustrated from the numerical simulations that the proposed plastic shear strain and confinement-dependent dilation angle model in combination with the calibrated CWFS model implemented in FLAC can reasonably reveal both rock mass failure and displacement distribution in vicinity of the excavation simultaneously. The simulation results are in good agreement with the field observations and displacement measurement data. 展开更多
关键词 hard rocks brittle failure deformation dilation angle model confinement plastic shear strain mine-by test tunnel
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Strength and deformation behaviour of coarse-grained soil by true triaxial tests 被引量:7
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作者 施维成 朱俊高 +1 位作者 赵仲辉 刘汉龙 《Journal of Central South University》 SCIE EI CAS 2010年第5期1095-1102,共8页
In order to investigate the influence of intermediate principal stress on the stress-strain and strength behaviour of a coarse-grained soil, a series of true triaxial tests were performed. The tests were conducted in ... In order to investigate the influence of intermediate principal stress on the stress-strain and strength behaviour of a coarse-grained soil, a series of true triaxial tests were performed. The tests were conducted in a recently developed true triaxial apparatus with constant minor principal stress σ3 and constant value of intermediate principal stress ratio b=(σ2-σ3)/(σ1-σ3) (al is the vertical stress, and % is the horizontal stress). It is found that the intermediate principal strain, ε2, increases from negative to positive value with the increase of parameter b from zero to unity under a constant minor principal stress. The minor principal strain, ε3, is always negative. This implies that the specimen exhibits an evident anisotropy. The relationship between b and friction angle obtained from the tests is different from that predicted by LADE-DUNCAN and MATSUOKA-NAKAI criteria. Based on the test results, an empirical equation of g(b) that is the shape function of the failure surface on re-plane was presented. The proposed equation is verified to be reasonable by comparing the predicted results using the equation with true triaxial test results of soils, such as coarse-grained soils in this study, sands and gravels in other studies. 展开更多
关键词 cohesionless soil coarse-grained soil true triaxial test STRENGTH deformation failure criterion
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Deformation Mechanism of Bimodal Structured 2205 Duplex Stainless Steel in Two Yield Stages
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作者 盛捷 DU Mingchen +7 位作者 LI Yufeng MA Guocai CHEN Weiqian ZHENG Yuehong ZHAN Faqi REN Junqiang G I Raab 喇培清 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第1期184-191,共8页
A kind of micro/nanostructured 2205 duplex stainless steel(DSS)with uniform distribution of nanocrystals was prepared via aluminothermic reaction method.The analysis of stress-strain curve showed that the fracture str... A kind of micro/nanostructured 2205 duplex stainless steel(DSS)with uniform distribution of nanocrystals was prepared via aluminothermic reaction method.The analysis of stress-strain curve showed that the fracture strength and elongation of the specimen were 946 MPa and 24.7%,respectively.At present,the research on microstructure of bimodal 2205 DSS at room temperature(RT)mainly depended on scanning electron microscope(SEM)observation after loading experiments.The test result indicates that there are two different yield stages in stress-strain curve of specimen during tensile process.The microstructure of duplex bimodal structured stainless steel consists of two pairs of soft hard regions and phases.By studying deformation mechanism of bimodal structured stainless steel,the interaction between soft phase and hard phase are discussed.The principle of composition design and microstructure control of typical duplex stainless steel is obtained,which provides an important research basis for designing of advanced duplex stainless steel. 展开更多
关键词 2205 duplex stainless steel bimodal structure in-situ tensile test deformation mechanism two different yield stages
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Permanent deformation response parameters of asphalt mixtures for a new mix-confined repeated load test 被引量:2
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作者 廖公云 杨毅文 +1 位作者 黄晓明 向晋源 《Journal of Central South University》 SCIE EI CAS 2013年第5期1434-1442,共9页
The main objective of this work is to propose new mixture response parameters and to compare correlations with rut depths and sensitivity of permanent deformation response parameters based on field extracted cores and... The main objective of this work is to propose new mixture response parameters and to compare correlations with rut depths and sensitivity of permanent deformation response parameters based on field extracted cores and lab-mixed duplicates. A new "mix-confined" test is developed and four new parameters for this test are proposed. Correlation coefficients with rut depths and coefficients of variation (sensitivity) are compared between the four new and two existing parameters. Some parameters are recommended to be used for the newly developed test. The results show that, newly developed test can capture the changes of permanent deformation of asphalt mixtures. Only one new parameter (D1 of Stephen Price model) and one existing parameter (flow number, Fn ) have strong correlations with rut depths of asphalt pavements (R2 greater than 0.7) and have relative small sensitivity (coefficient of variation, COV, less than 30%). For polymer modified asphalt mixtures, the parameter D1 rather than Fn should be used. These findings can be used to check the permanent deformation of asphalt mixture during the mix design. 展开更多
关键词 mixture response parameters permanent deformation asphalt mixture mix-confined test correlation coefficient sensitivity
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Effects of confining pressure and temperature on strength and deformation behavior of frozen saline silty clay
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作者 Gang Wu GuoYu Li +4 位作者 Hui Bing Dun Chen YaPeng Cao LiYun Tang HaiLiang Jia 《Research in Cold and Arid Regions》 CSCD 2023年第1期1-10,共10页
Buildings are always affected by frost heave and thaw settlement in cold regions,even where saline soil is present.This paper describes the triaxial testing results of frozen silty clay with high salt content and exam... Buildings are always affected by frost heave and thaw settlement in cold regions,even where saline soil is present.This paper describes the triaxial testing results of frozen silty clay with high salt content and examines the in-fluence of confining pressure and temperature on its mechanical characteristics.Conventional triaxial compression tests were conducted under different confining pressures(0.5–7.0 MPa)and temperatures(-6℃,-8℃,-10℃,and-12℃).The test results show that when the confining pressure is less than 1 MPa,the frozen saline silty clay is dominated by brittle behavior with the X-shaped dilatancy failure mode.As the confining pressure increases,the sample gradually transitions from brittle to plastic behavior.The strength of frozen saline silty clay rises first and then decreases with increasing confining pressure.The improved Duncan-Chang hyperbolic model can describe the stress-strain relationship of frozen saline silty clay.And the parabolic strength criterion can be used to describe the strength evolution of frozen saline silty clay.The function relation of strength parameters with temperature is obtained by fitting,and the results of the parabolic strength criterion are in good agreement with the experimental results,especially when confining pressure is less than 5 MPa.Therefore,the study has important guiding significance for design and construction when considering high salinity soil as an engineering material in cold regions. 展开更多
关键词 Super saline soil Frozen saline soil Triaxial compression test Confining pressure STRENGTH deformation characteristics
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Analysis on the deformation and fracture behavior of carbon steel by in situ tensile test 被引量:1
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作者 Fan Li Haibo Huang 《Journal of University of Science and Technology Beijing》 CSCD 2006年第6期504-507,共4页
The deformation and fracture behaviors of low-carbon steel, medium-carbon steel, and high-carbon steel were studied on internal microstructure using the scanning electron microscopy in situ tensile test. The microstru... The deformation and fracture behaviors of low-carbon steel, medium-carbon steel, and high-carbon steel were studied on internal microstructure using the scanning electron microscopy in situ tensile test. The microstructure mechanism of their deformation and fracture behavior was analyzed. The results show that the deformation and fracture behavior of low-carbon steel depends on the grain size of ferrite, the deformation and fracture behavior of medium-carbon steel depends on the size of ferrite grain and pearlite lump, and the deformation and fracture behavior of high-carbon steel depends on the size of pearlite lump and the pearlitic interlamellar spacing. 展开更多
关键词 carbon steel deformation FRACTURE microstructure mechanism in situ tensile test
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The Deformation Analysis of the 3D Alignment Control Network Based on the Multiple Congruence Models
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作者 Xudong ZHANG Wenjun CHEN +5 位作者 Xiaodong ZHANG Yajun ZHENG Bin ZHANG Shaoming WANG Jiandong YUAN Guozhen SUN 《Journal of Geodesy and Geoinformation Science》 CSCD 2023年第2期21-31,共11页
In the construction and maintenance of particle accelerators,all the accelerator elements should be installed in the same coordinate system,only in this way could the devices in the actual world be consistent with the... In the construction and maintenance of particle accelerators,all the accelerator elements should be installed in the same coordinate system,only in this way could the devices in the actual world be consistent with the design drawings.However,with the occurrence of the movements of the reinforced concrete cover plates at short notice or building deformations in the long term,the control points upon the engineering structure will be displaced,and the fitness between the subnetwork and the global control network may be irresponsible.Therefore,it is necessary to evaluate the deformations of the 3D alignment control network.Different from the extant investigations,in this paper,to characterize the deformations of the control network,all of the congruent models between the points measured in different epochs have been identified,and the congruence model with the most control points is considered as the primary or fundamental model,the remaining models are recognized as the additional ones.Furthermore,the discrepancies between the primary S-transformation parameters and the additional S-transformation parameters can reflect the relative movements of the additional congruence models.Both the iterative GCT method and the iterative combinatorial theory are proposed to detect multiple congruence models in the control network.Considering the actual work of the alignment,it is essential to identify the competitive models in the monitoring network,which can provide us a hint that,even the fitness between the subnetwork and the global control network is good,there are still deformations which may be ignored.The numerical experiments show that the suggested approaches can describe the deformation of the 3D alignment control network roundly. 展开更多
关键词 similarity transformation 3D alignment control network deformation analysis hypothesis testing iterative global congruence test iterative combinatorial theory
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Post-Processing of InSAR Deformation Time Series Using Clustering-Based Pattern Identification
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作者 Wenxin Zhu Fengming Hu Feng Xu 《Journal of Beijing Institute of Technology》 EI CAS 2023年第6期704-716,共13页
Multi-temporal synthetic aperture radar interferometry(MT-InSAR)is a standard technique for mapping clustering and wide-scale deformation.A linear model is often used in phase unwrapping to overcome the underdetermina... Multi-temporal synthetic aperture radar interferometry(MT-InSAR)is a standard technique for mapping clustering and wide-scale deformation.A linear model is often used in phase unwrapping to overcome the underdetermination.It’s difficult to identify different types of nonlinear deformation.However,the interpretation of nonlinear deformation is very important in monitoring potential risk.This paper introduces a comprehensive approach for identifying and interpreting different types of deformation within InSAR datasets,integrating initial clustering and classification simplification.Initial classification is performed using the K-means clustering method to cluster the collected InSAR deformation time-series data.Then we use F test and Anderson-Darling test(AD test)to simplify the clusters after initial classification.This technique distinctly discerns the changing trends of deformation signals,thereby providing robust support for interpreting potential deformation scenarios within observed InSAR regions. 展开更多
关键词 multi-temporal synthetic aperture radar interferometry(MT-InSAR) machine learning hypothesis test nonlinear deformation
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Research on Well Testing Interpretation of Low Permeability Deformed Dual Medium Reservoir
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作者 Meinan Wang Yue Xie +2 位作者 Rui Zhang Guohao Zhang Jianguo Liu 《Open Journal of Applied Sciences》 2023年第11期2141-2148,共8页
Considering the influence of quadratic gradient term and medium deformation on the seepage equation, a well testing interpretation model for low permeability and deformation dual medium reservoirs was derived and esta... Considering the influence of quadratic gradient term and medium deformation on the seepage equation, a well testing interpretation model for low permeability and deformation dual medium reservoirs was derived and established. The difference method was used to solve the problem, and pressure and pressure derivative double logarithmic curves were drawn to analyze the seepage law. The research results indicate that the influence of starting pressure gradient and medium deformation on the pressure characteristic curve is mainly manifested in the middle and late stages. The larger the value, the more obvious the upward warping of the pressure and pressure derivative curve;the parameter characterizing the dual medium is the crossflow coefficient. The channeling coefficient determines the time and location of the appearance of the “concave”. The smaller the value, the later the appearance of the “concave”, and the more to the right of the “concave”. 展开更多
关键词 Low Permeability Oil Reservoirs deformation Medium Dual Media Cross Flow Coefficient Well testing Interpretation Model
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A METHOD TO QUANTIFY CRAZING DEFORMATION BY TENSILE TESTS FOR POLYSTYRENE/POLYOLEFIN ELASTOMER IMMISCIBLE BLENDS
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作者 方征平 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2007年第4期387-392,共6页
A method to quantify crazing deformations by tensile tests for polystyrene (PS) and polyolefin elastomer (POE) blends was investigated. The toughness of PS/POE blends, reflected by the Charpy impact strength, incr... A method to quantify crazing deformations by tensile tests for polystyrene (PS) and polyolefin elastomer (POE) blends was investigated. The toughness of PS/POE blends, reflected by the Charpy impact strength, increased with the content of POE. SEM micrographs showed the poor compatibility between PS and POE. In simple tensile tests, it is very easy to achieve the ratio of crazing deformation, i.e. K by measuring the size changes of samples. The K values decreased with increasing the content of POE, and the deformations of PS/POE blends were dominated by crazing. The plots of the change of volume (△V) against longitudinal variation (△I) showed a linear relationship, and the slope of lines decreased with the content of POE. Measuring samples at the tensile velocities of 5 mm/min, 50 mm/min, and 500 mm/min respectively, the K values kept unchanged for each PS/POE blends. 展开更多
关键词 Crazing deformation Shear yielding deformation Tensile test Polystyrene (PS) Polyolefin elastomer (POE) Blend.
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Physical model test and application of 3D printing rock-like specimens to laminated rock tunnels
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作者 Yun Tian Weizhong Chen +3 位作者 Hongming Tian Xiaoyun Shu Linkai He Man Huang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第11期4625-4637,共13页
Weak structural plane deformation is responsible for the non-uniform large deformation disasters in layered rock tunnels,resulting in steel arch distortion and secondary lining cracking.In this study,a servo biaxial t... Weak structural plane deformation is responsible for the non-uniform large deformation disasters in layered rock tunnels,resulting in steel arch distortion and secondary lining cracking.In this study,a servo biaxial testing system was employed to conduct physical modeling tests on layered rock tunnels with bedding planes of varying dip angles.The influence of structural anisotropy in layered rocks on the micro displacement and strain field of surrounding rocks was analyzed using digital image correlation(DIC)technology.The spatiotemporal evolution of non-uniform deformation of surrounding rocks was investigated,and numerical simulation was performed to verify the experimental results.The findings indicate that the displacement and strain field of the surrounding layered rocks are all maximized at the horizontal bedding planes and decrease linearly with the increasing dip angle.The failure of the layered surrounding rock with different dip angles occurs and extends along the bedding planes.Compressive strain failure occurs after excavation under high horizontal stress.This study provides significant theoretical support for the analysis,prediction,and control of non-uniform deformation of tunnel surrounding rocks. 展开更多
关键词 Bedding plane Three-dimensional(3D)printing Physical model test Non-uniform deformation Digital imaging correlation(DIC)
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Deformation mechanism at impact test of Al-11% Si alloy processed by equal-channel angular pressing with rotary die 被引量:2
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作者 马爱斌 Y. NISHIDA +3 位作者 江静华 N. SAITO I. SHIGEMATSU A. WATAZU 《中国有色金属学会会刊:英文版》 EI CSCD 2007年第1期104-109,共6页
Al-11%Si(mass fraction)alloy was transformed into a ductile material by equal-channel angular pressing(ECAP)with a rotary die.Two mechanisms at impact test,slip deformation by dislocation motion and grain boundary sli... Al-11%Si(mass fraction)alloy was transformed into a ductile material by equal-channel angular pressing(ECAP)with a rotary die.Two mechanisms at impact test,slip deformation by dislocation motion and grain boundary sliding,were discussed.The ultrafine grains with modified grain boundaries and the high content of fine particles(<1μm)were necessary for attaining high absorbed energy.The results contradict the condition of slip deformation by dislocation motion and coincide with that of grain boundary sliding.Many fine zigzag lines like a mosaic were observed on the side surface of the tested specimens.These observed lines may show grain boundaries appeared by the sliding of grains. 展开更多
关键词 铝合金 变形行为 微观结构 晶界滑动
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