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On the installation of an in situ large-scale vertical SEALing (VSEAL) experiment on bentonite pellet-powder mixture
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作者 Nadia Mokni Justo Cabrera Frédéric Deleruyelle 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第9期2388-2401,共14页
Recently,the Institute for Radiological protection and Nuclear Safety(IRSN)has launched VSEAL(Vertical SEALing)project to investigate the impact of gas migration on the long-term performance of bentonite based vertica... Recently,the Institute for Radiological protection and Nuclear Safety(IRSN)has launched VSEAL(Vertical SEALing)project to investigate the impact of gas migration on the long-term performance of bentonite based vertical sealing systems(VSS).The first VSEAL in situ test was emplaced in IRSN’s Underground Research Laboratory(URL)in Tournemire(France)in 2019 and was equipped with 76 wired and wireless sensors.The test is still in progress,but the collected set of data provides already valuable information of the hydro-mechanical behavior of VSS during hydration.The swelling core consists of a mixture of highdensity pellets and powder of MX80 bentonite in a ratio of 80/20(in dry mass).An innovative method was adopted to drill a 1-m diameter and w10-m deep shaft in order to minimize the rock perturbation at the sidewalls.Because a specific protocol was adopted to install the bentonite mixture together with a careful characterization of the core during construction,VSEAL 1 constitutes the unique in situ sealing test with a well-known initial structural distribution of the pellets and the powder.Some heterogeneities occurred within the experiment during the installation process:a damaged zone developed around the shaft walls due to the interruption of the installation operations caused by COVID19 lockdown in France;a technological gap with a variable thickness between the last pellets layer and the top confining lid and a heterogeneous distribution of the bentonite powder at some layers inducing large inter pellets voids close to the bentonite-rock interface.Artificially injected water volume,relative humidity,water content and swelling pressure in both radial and axial directions were monitored.Comparison of the results showed that the presence of installation-induced heterogeneities led to the generation of preferential flow paths that influenced the swelling pressure evolution at radial and axial directions. 展开更多
关键词 Bentonite pellet-powder mixture HETEROGENEITIES Technological gap Seals in situ test
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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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Comparison of in situ Shear Test and In-Lab Triaxial Shear Test of Compacted Rockfill
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作者 闫宗岭 邱贤德 余永强 《Journal of Southwest Jiaotong University(English Edition)》 2003年第2期165-171,共7页
The in situ shear test and in-lab triaxial shear test on compacted rockfill of Fuling safety embankment were carried out and their advantages and disadvantages were compared. The discreteness of cohesive force C and i... The in situ shear test and in-lab triaxial shear test on compacted rockfill of Fuling safety embankment were carried out and their advantages and disadvantages were compared. The discreteness of cohesive force C and internal frictional angle by in situ shear test is much severer than that by in-lab triaxial shear test. The consolidation of in-lab triaxial shear test is bigger than actual consolidation in rockfill engineerings, so the confining pressure should be reduced to a low level in-lab triaxial shear test. 展开更多
关键词 compacted rockfill EMBANKMENT in situ shear test in-lab triaxial shear test Three Gorges project
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Application of ultrasonic fatigue technology in very-high-cycle fatigue testing of aviation gas turbine engine blade materials:A review
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作者 ZHAO JiuCheng WAN Jie +2 位作者 ZHANG ShiZhong YAN ChuLiang ZHAO HongWei 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2024年第5期1317-1363,共47页
The need for very-high-cycle fatigue(VHCF)testing up to 1010cycles of aviation gas turbine engine blade materials under combined mechanical loads and complex environments has encouraged the development of VHCF testing... The need for very-high-cycle fatigue(VHCF)testing up to 1010cycles of aviation gas turbine engine blade materials under combined mechanical loads and complex environments has encouraged the development of VHCF testing instrumentation and technology.This article begins with a comprehensive review of the existing available techniques that enable VHCF testing.Recent advances in ultrasonic fatigue testing(UFT)techniques are highlighted,containing their new capabilities and methods for single load,multiaxial load,variable amplitude fatigue,and combined cycle fatigue.New techniques for conducting UFT in high-temperature,humid environments,and corrosive environments are summarized.These developments in mechanical loading and environmental building techniques provide the possibility of laboratory construction for real service conditions of blade materials.New techniques that can be used for in situ monitoring of VHCF damage are summarized.Key issues in the UFT field are presented,and countermeasures are collated.Finally,the existing problems and future trends in the field are briefly described. 展开更多
关键词 aviation gas turbine engine blade materials ultrasonic fatigue very-high-cycle fatigue high-temperature complex stress in situ testing
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Ground-borne vibration generated by high-speed train viaduct systems in soft-upper/hard-lower rock strata 被引量:4
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作者 XING Meng-ting WANG Ping +2 位作者 ZHAO Cai-you WU Xue KANG Xiu-shan 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第7期2140-2157,共18页
An experimental study and theoretical analysis were carried out to explore the ground-borne vibration generated by elevated high-speed railway in rock strata.Taking a typical rail line constructed on rock area in Chin... An experimental study and theoretical analysis were carried out to explore the ground-borne vibration generated by elevated high-speed railway in rock strata.Taking a typical rail line constructed on rock area in China as the research object,a set of field tests was performed on Rizhao-Lankao High-Speed Railway,the bridge and ground vibrations were measured as trains passed at 330−340 km/h,then the transferring law and spatial distribution under individual frequencies were investigated.The experiment results indicate that the bridge frequency spectrum exhibited relatively high-frequency vibration peaks caused by short-wavelength irregularity;ground vibration farther than 30 m away can be amplified with a higher frequency and numerous components.Furthermore,the wave propagation equation of a stratified rock strata was established based on direct-stiffness method to explore the vibration attenuation rules via frequency-domain analysis.It is found that the rock area has a weaker correlation between vibration transmissibility and frequency,thicker and harder rock strata loss their vibration attenuation capacity.It can be concluded that the high-speed railways induced vibration on rock strata shows a wide frequency band and large amplitude,the design of reducing vibration aimed at specific frequency is important according to next more detailed numerical study. 展开更多
关键词 rock stratum vibration and wave elevated high-speed railways in situ test transferring law
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Unloading performances and stabilizing practices for columnar jointed basalt:A case study of Baihetan hydropower station 被引量:4
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作者 Qixiang Fan Xiating Feng +2 位作者 Wenlin Weng Yilin Fan Quan Jiang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2017年第6期1041-1053,共13页
The columnar jointed rock mass(CJR), composed of polygonal cross-sectional columns cut by several groups of joints in various directions, was exposed during the excavations of the Baihetan hydropower station, China. I... The columnar jointed rock mass(CJR), composed of polygonal cross-sectional columns cut by several groups of joints in various directions, was exposed during the excavations of the Baihetan hydropower station, China. In order to investigate the unloading performances and the stability conditions during excavation of the columns, an experimental field study was performed. Firstly, on-site investigations indicated that the geotechnical problems, including rock relaxation, cracking and collapse, were the most prominent for the CJR Class I that contains intensive joint network and the smallest column sizes.Comprehensive field tests, including deformation measurement by multi-point extensometers, ultrasonic wave testing, borehole television observation and stress monitoring of rock anchors, revealed that the time-dependent relaxation of the CJRs was marked. The practical excavation experiences for the Baihetan columnar jointed rock masses, such as blasting scheme, supporting time of shotcrete and rock bolts, were presented in the excavations of the diversion tunnels. These detailed investigations and practical construction experiences can provide helpful information for similar geotechnical works in jointed rock mass. 展开更多
关键词 Columnar jointed basalt Diversion tunnels Rock unloading in situ test Hydropower station
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Effects of zinc on static and dynamic mechanical properties of copper-zinc alloy 被引量:1
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作者 马志超 赵宏伟 +1 位作者 鲁帅 程虹丙 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第7期2440-2445,共6页
The effects of adding alloy element zinc on the static and dynamic mechanical properties of copper-zinc alloy were investigated. Tensile and low cycle fatigue behaviors of the C11000 copper and H63 copper-zinc alloy w... The effects of adding alloy element zinc on the static and dynamic mechanical properties of copper-zinc alloy were investigated. Tensile and low cycle fatigue behaviors of the C11000 copper and H63 copper-zinc alloy were obtained by using a miniature tester that combined the functions of in situ tensile and fatigue testing. A piezoelectric actuator was adopted as the actuator for the fatigue testing, and the feasibility of the fatigue actuator was verified by the transient harmonic response analysis based on static tensile preload and dynamic sinusoidal load. The experimental results show that the yield strength and tensile strength of the C11000 copper are improved after adding 37%(mass fraction) zinc, and H63 copper-zinc alloy presents more obvious cyclic hardening behavior and more consumed irreversible plastic work during each stress cycle compared with C11000 copper for the same strain controlled cycling. Additionally, based on the Manson-Coffin theory, the strain-life equations of the two materials were also obtained. C11000 copper and H63 copper-zinc alloy show transition life of 16832 and 1788 cycles, respectively. 展开更多
关键词 tensile behavior low cycle fatigue copper alloy in situ test piezoelectric actuator
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Seasonal influence on cone penetration test: An unsaturated soil site example
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作者 Heraldo Luiz Giacheti Renan Cravera Bezerra +1 位作者 Breno Padovezi Rocha Roger Augusto Rodrigues 《Journal of Rock Mechanics and Geotechnical Engineering》 CSCD 2019年第2期361-368,共8页
Interpretation of electric cone penetration test(CPT) based pore water pressure measurement(CPTu) is well established for soils with behavior that follows classical soil mechanics. The literature on the interpretation... Interpretation of electric cone penetration test(CPT) based pore water pressure measurement(CPTu) is well established for soils with behavior that follows classical soil mechanics. The literature on the interpretation of these tests performed on unsaturated tropical soils is limited, and little is known about the influence of soil suction on in situ test data. In this context, the CPT data are presented and discussed to illustrate the seasonal variability in an unsaturated tropical soil site. The test data show that soil suction significantly influenced CPT data up to a depth of 4 m at the study site. It shows the importance of considering seasonal variability in unsaturated soil sites caused by soil suction, which was related to water content through a soil-water retention curve(SWRC). It is also important to consider this aspect in the interpretation of CPT data from these soils. 展开更多
关键词 Site investigation in situ testing Cone penetration test (CPT) Unsaturated soil SUCTION VARIABILITY
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Geotechnical behavior of the MSW in Tianziling landfill
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作者 朱向荣 金建明 方鹏飞 《Journal of Zhejiang University Science》 EI CSCD 2003年第3期324-330,共7页
The valley shaped Tianziling landfill of Hangzhou in China built in 1991 to dispose of municipal solid waste (MSW) was designed for a service life of 13 years. The problem of waste landfill slope stability and expansi... The valley shaped Tianziling landfill of Hangzhou in China built in 1991 to dispose of municipal solid waste (MSW) was designed for a service life of 13 years. The problem of waste landfill slope stability and expansion must be considered from the geotechnical engineering point of view, for which purpose, it is necessary to understand the geotechnical properties of the MSW in the landfill, some of whose physical properties were measured by common geotechnical tests, such as those on unit weight, water content, organic matter content, specific gravity, coefficient of permeability, compressibility, etc. The mechanical properties were studied by direct shear test, triaxial compression test, and static and dynamic penetration tests. Some strength parameters for engineering analysis were obtained. 展开更多
关键词 Municipal solid waste (MSW) Engineering properties Laboratory test in situ test
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Forming Limit Stress Diagram Prediction of Aluminum Alloy 5052 Based on GTN Model Parameters Determined by In Situ Tensile Test 被引量:21
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作者 HE Min LI Fuguo WANG Zhigang 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2011年第3期378-386,共9页
The conventional forming limit diagram (FLD) is described as a plot of major strain versus minor strain. However, FLD is dependent on forming history and strain path. In the present study, a forming limit stress-bas... The conventional forming limit diagram (FLD) is described as a plot of major strain versus minor strain. However, FLD is dependent on forming history and strain path. In the present study, a forming limit stress-based diagram (FLSD) has been adopted to predict the fracture limit of aluminum alloy (AA) 5052-O1 sheet. Nakazima test is simulated by plastic constitutive formula derived from the modified Gurson-Tvergaard-Needleman (GTN) model. An in situ tensile test with scanning electron microscope (SEM) is proposed to determine the parameters in GTN model. The damage evolution is observed and recorded, and the parameters of GTN model are identified through counting void fraction at three damage stages of AA5052-O 1. According to the experimental results, the original void volume fraction, the volume fraction of potential nucleated voids, the critical void volume fraction, the void volume fraction at the final failure of material are assigned as 0.002 918, 0.024 9, 0.030 103, 0.048 54, respectively. The stress and strain are obtained at the last loading step before crack. FLSD and FLD of AA5052-O 1 are plotted. Compared with the experimental Nakazima test and uniaxial tensile test, the predicted results show a good agreement. The parameters determined by in situ tensile test can be applied to the research of the forming limit for ductile metals. 展开更多
关键词 forming limit stress diagram GTN model in situ tensile test void damage aluminum alloy 5052-O1 sheet metal forming
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A miniature triaxial apparatus for investigating the micromechanics of granular soils with in situ X-ray micro-tomography scanning 被引量:3
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作者 Zhuang CHENG Jianfeng WANG +1 位作者 Matthew Richard COOP Guanlin YE 《Frontiers of Structural and Civil Engineering》 SCIE EI CSCD 2020年第2期357-373,共17页
The development of a miniature triaxial apparatus is presented.In conjunction with an X-ray microtomography(termed as X-ray fiCT hereafter)facility and advanced image processing techniques,this apparatus can be used f... The development of a miniature triaxial apparatus is presented.In conjunction with an X-ray microtomography(termed as X-ray fiCT hereafter)facility and advanced image processing techniques,this apparatus can be used for in situ investigation of the micro-scale mechanical behavior of granular soils under shear.The apparatus allows for triaxial testing of a miniature dry sample with a size of 8 mm x 16 mm(diameter x height).In situ triaxial testing of a 0.4-0.8 mm Leighton Buzzard sand(LBS)under a constant confining pressure of 500 kPa is presented.The evolutions of local porosities(i.e.,the porosities of regions associated with individual particles),particle kinematics(i.e.,particle translation and particle rotation)of the sample during the shear are quantitatively studied using image processing and analysis techniques.Meanwhile,a novel method is presented to quantify the volumetric strain distribution of the sample based on the results of local porosities and particle tracking.It is found that the sample,with nearly homogenous initial local porosities,starts to exhibit obvious inhomogeneity of local porosities and localization of particle kinematics and volumetric strain around the peak of deviatoric stress.In the post-peak shear stage,large local porosities and volumetric dilation mainly occur in a localized band.The developed triaxial apparatus,in its combined use of X-ray|iCT imaging techniques,is a powerful tool to investigate the micro-scale mechanical behavior of granular soils. 展开更多
关键词 triaxial apparatus X-ray fiCT in situ test micro-scale mechanical behavior granular soils
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Application of wave equation theory to improve dynamic cone penetration test for shallow soil characterisation 被引量:1
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作者 Miguel Angel Benz Navarrete Pierre Breul Roland Gourvès 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2022年第1期289-302,共14页
Among the geotechnical in situ tests,the dynamic penetration test(DPT)is commonly used around the world.However,DPT remains a rough technique and provides only one failure parameter:blow count or cone resistance.This ... Among the geotechnical in situ tests,the dynamic penetration test(DPT)is commonly used around the world.However,DPT remains a rough technique and provides only one failure parameter:blow count or cone resistance.This paper presents an improvement of the dynamic cone penetration test(DCPT)for soil characterisation based on the wave equation theory.Implemented on an instrumented lightweight dynamic penetrometer driving with variable energy,the main process of the test involves the separation and reconstruction of the waves propagating in the rods after each blow and provides a dynamic cone load-penetration(DCLT)curve.An analytical methodology is used to analyse this curve and to estimate additional strength and deformation parameters of the soil:dynamic and pseudo-static cone resistances,deformation modulus and wave velocity.Tests carried out in the laboratory on different specimens(wood,concrete,sand and clay)in an experimental sand pit and in the field demonstrated that the resulting DCLT curve is reproducible,sensitive and reliable to the test conditions(rod length,driving energy,etc.)as well as to the soil properties(nature,density,etc.).Obtained results also showed that the method based on shock polar analysis makes it possible to evaluate mechanical impedance and wave velocity of soils,as demonstrated by the comparisons with cone penetration test(CPT)and shear wave velocity measurements made in the field.This technique improves the method and interpretation of DPT and provides reliable data for shallow foundation design. 展开更多
关键词 in situ test Dynamic cone penetrometer P.A.N.D.A. Wave equation Wave decoupling Dynamic cone load-penetration(DCLT)curve
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Loading-unloading test analysis of anisotropic columnar jointed basalts 被引量:4
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作者 Zhi-gang SHAN Sheng-jie DI 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2013年第8期603-614,共12页
To evaluate the columnar jointed basalts in the dam site of Baihetan hydropower station in southwest China, we developed a basic conceptual model of single jointed rock mass. Considering that the rock mass deformation... To evaluate the columnar jointed basalts in the dam site of Baihetan hydropower station in southwest China, we developed a basic conceptual model of single jointed rock mass. Considering that the rock mass deformation consists of rock block deformation and joints deformation, the linear mechanical characteristics of the cell (including the elastic joints and the nonlinear mechanical behaviors of the cell) with a combined frictional-elastic interface were analyzed. We developed formulas to calculate the rock block deformation, which can be adapted for multiple jointed rock mass and columnar jointed basalts. The formulas are effective in calculating the equivalent modulus of multiple jointed rock mass, and precisely reveal the anisotropic properties of columnar jointed basalts. Furthermore, the in situ rigid bearing plate tests were analyzed and calculated, and the types of loading-unloading curves and the equivalent modulus along different directions of columnar jointed basalts were obtained. The analytical results are in close compliance with the test results. 展开更多
关键词 Columnar jointed basalts in situ test Joint stiffness Loading-unloading ANISOTROPY
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Microstructure, property and deformation and fracture behavior of 800 MPa complex phase steel with different coiling temperatures 被引量:2
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作者 Jian-zhong Xue Zheng-zhi Zhao +5 位作者 Di Tang Hui Li Hao-hong Wu Wei-liang Xiong Liang Liang Yao Huang 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2021年第3期346-359,共14页
The microstructure characteristics and properties(especially hole expansion property)of 800 MPa hot-rolled complex phase steel with different coiling temperatures were studied.The microstructure consisted of polygonal... The microstructure characteristics and properties(especially hole expansion property)of 800 MPa hot-rolled complex phase steel with different coiling temperatures were studied.The microstructure consisted of polygonal ferrite and precipitates when the steel was coiled at 550℃,and when the steel was coiled between 460–520℃,the microstructure was composed of granular bainite and martensite and austenite(M/A)islands.The morphology of the crack was analyzed by scanning electron microscopy,and the in situ scanning electron microscope tensile test was used to find out the fracture mechanism and deformation behavior of the steel with different coiling temperatures.When the steel was coiled at 550℃,the cracks initiated at the ferrite grain boundary and propagated through the grains or along the grain boundaries.When the steel was coiled at 520℃,the cracks first initiated at the junction of ferrite and M/A island and then propagated through the grains.The steel coiled at 520℃ has quite good mechanical properties and relatively high hole expansion ratio. 展开更多
关键词 Complex phase steel Coiling temperature Strength in situ tensile test Hole expansion ratio CRACK
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Discrete twinning dynamics and size-dependent dislocation-to twin transition in body-centred cubic tungsten 被引量:2
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作者 Jiangwei Wang Anik H.M.Faisal +6 位作者 Xiyao Li Youran Hong Qi Zhu Hongbin Bei Ze Zhang Scott X Mao Christopher R.Weinberger 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2022年第11期33-40,共8页
Body-centred cubic(BCC) metals are known to have unstable intrinsic stacking faults and high resistance to deformation twinning, which can strongly influence their twinning behaviour. Though twinning mechanisms of BCC... Body-centred cubic(BCC) metals are known to have unstable intrinsic stacking faults and high resistance to deformation twinning, which can strongly influence their twinning behaviour. Though twinning mechanisms of BCC metals have been investigated for more than 60 years, the atomistic level dynamics of twinning remains under debate, especially regarding its impact on competition between twinning and slip. Here, we investigate the atomistic level dynamics of twinning in BCC tungsten(W) nanowires using in situ nanomechanical testing. Quantitative experimental studies directly visualize that deformation twins in W nanowires have a minimum size of six-layers and grow in increments of approximately three-layers at a time, in contrast to the layer-by-layer growth of deformation twins in face-centred cubic metals. These unique twinning dynamics induces a strong competition with ordinary dislocation slip,as exhibited by a size-dependent dislocation-to-twin transition in W nanowires, with a transition size of ~40 nm. Our work provides physical insight into the dynamics of twinning at the atomic level, as well as a size-dependent dislocation-twinning competition, which have important implications for the plastic deformation in a broad class of BCC metals and alloys. 展开更多
关键词 Body-centred cubic Deformation twin Twinning dynamics Dislocation-to-twin transition in situ nanomechanical testing
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Water content distribution in the surface layer of Maoping slope
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作者 LIU Yuewu CHEN Huixin +3 位作者 LIU Qingquan GONG Xin ZHANG Dawei LI Lianxiang 《Science China(Technological Sciences)》 SCIE EI CAS 2005年第z1期157-170,共14页
The water content distribution in the surface layer of Maoping slope has been studied by testing the water content at 31 control sites.The water content profiles at these sites have also been determined.The water cont... The water content distribution in the surface layer of Maoping slope has been studied by testing the water content at 31 control sites.The water content profiles at these sites have also been determined.The water content distributions at different segments have been obtained by using the Kriging method of geostatistics.By comparing the water content distributions with the landform of the slope,it was shown that the water content is closely dependent on the landform of the slope.The water content distribution in the surface layer provided a fundamental basis for landslide predication and treatment. 展开更多
关键词 LANDSLIDE water content in situ test Kriging method geostatistics.
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Support elements in conventional tunneling–Focus on long-term behavior
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作者 Robert Galler Stefan Lorenz 《Underground Space》 SCIE EI 2018年第4期277-287,共11页
Owing to increasing traffic and the need for constructing second tunnel tubes including corresponding cross-passages,where only one tube existed thus far,sampling of tunnel-lining materials with an age of 30–40 years... Owing to increasing traffic and the need for constructing second tunnel tubes including corresponding cross-passages,where only one tube existed thus far,sampling of tunnel-lining materials with an age of 30–40 years has been made possible.Laboratory and in situ tests were carried out to evaluate the long-term effects of the tunnel linings.This paper presents the outcomes regarding the long-term behav-ior of support elements and membranes after performing strength tests on inner and outer lining concrete samples,flat jack tests,rock bolt tests,and tests on re-extracted sheet membranes,as well as geotextiles.Furthermore,the interface connection mechanical behavior in a double-shell-lined tunnel was investigated with laboratory tests.The aim of this research was to determine the characteristics of sheet membranes and geotextiles in the case of reduced load-bearing capacity caused by degradation of the primary lining.The results provide information on the load-sharing effects of the interaction between the primary and secondary lining,depending on the waterproofing sheet membrane and geotextile properties.Based on the results,conclusions for new design approaches for underground infrastructure construction can be formulated. 展开更多
关键词 Tunnel lining Long-term behavior Concrete Sheet membrane Rock bolt Flat jack test in situ tests
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Effects of chloride on electrochemical and stress corrosion cracking behavior of 9Cr ferritic-martensitic steel
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作者 Zhen Zhang Zheng-fei Hu +4 位作者 Liang He Xiao-bo Zhang Xin-xian Fang Bao-sen Zhang Zhi-xin Ba 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2020年第6期719-731,共13页
The electrochemical and stress corrosion cracking behavior of 9Cr ferritic-martensitic steel is investigated in the chloride environment by using the traditional electrochemical method, the scanning vibrating electrod... The electrochemical and stress corrosion cracking behavior of 9Cr ferritic-martensitic steel is investigated in the chloride environment by using the traditional electrochemical method, the scanning vibrating electrode technique and the slow strain rate test (SSRT). Results of the static corrosion tests and corrosion morphology show that the prior austenite grain boundaries and martensite lath boundaries are the preferred sites for pit nucleation and growth in chloride environment. Results of SSRT coupled with insitu electrochemical test show that the transition from pitting corrosion to uniform corrosion, as well as the nucleation of stress corrosion crack, is the synergistic effects of the chloride and applied load. Stress corrosion cracking of the steel in the chloride environment can be divided into three different regions as follows: fast and uniform corrosion activ-ity, microcrack nucleation and propagation, and active crack growth regions. 展开更多
关键词 9Cr ferritic-martensitic steel CHLORIDE in situ electrochemical test Scanning vibrating electrode technique Stress corrosion cracking
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High elasticity of CsPbBr_(3) perovskite nanowires for flexible electronics
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作者 Xiaocui Li You Meng +5 位作者 Rong Fan Sufeng Fan Chaoqun Dang Xiaobin Feng Johnny C.Ho Yang Lu 《Nano Research》 SCIE EI CSCD 2021年第11期4033-4037,共5页
Due to the enhanced ambient structural stability and excellent optoelectronic properties, all-inorganic metal halide perovskite nanowires have become one of the most attractive candidates for flexible electronics, pho... Due to the enhanced ambient structural stability and excellent optoelectronic properties, all-inorganic metal halide perovskite nanowires have become one of the most attractive candidates for flexible electronics, photovoltaics and optoelectronics. Their elastic property and mechanical robustness become the key factors for device applications under realistic service conditions with various mechanical loadings. Here, we demonstrate that high tensile elastic strain (∼ 4% to ∼ 5.1%) can be achieved in vapor-liquid-solid-grown single-crystalline CsPbBr_(3) nanowires through in situ scanning electron microscope (SEM) buckling experiments. Such high flexural elasticity can be attributed to the structural defect-scarce, smooth surface, single-crystallinity and nanomechanical size effect of CsPbBr_(3) nanowires. The mechanical reliability of CsPbBr_(3) nanowire-based flexible photodetectors was examined by cyclic bending tests, with no noticeable performance deterioration observed after 5,000 cycles. The above results suggest great application potential for using all-inorganic perovskite nanowires in flexible electronics and energy harvesting systems. 展开更多
关键词 perovskite nanowire CsPbBr_(3) nanomechanics in situ testing ELASTICITY flexible electronics
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