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Revisiting scale effect on joint roughness coefficient and shear strength considering sampling methods and geometric characteristics 认领 引用 被引量：1
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作者 Qing Lü Xueheng Cai +2 位作者 Luxiang Wu Jun Zheng Bo Li 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2025年第5期2843-2856,共14页
The scale effect on shear strength of rock joints is well-documented.However,whether scale effects are negative,positive,or even exist or not is still controversial.Joint roughness significantly influences the shear s... The scale effect on shear strength of rock joints is well-documented.However,whether scale effects are negative,positive,or even exist or not is still controversial.Joint roughness significantly influences the shear strength of rock joints.Compared to the shear tests,using the joint roughness coefficient(JRC)and its roughness parameters offers a more convenient method for describing the scale effect on shear strength.However,it is crucial to understand that the scale effect mechanisms of JRC are distinct from those of shear strength.Therefore,this paper aims to clarify these distinct mechanisms.By digitally extracting roughness parameters from granite samples,it is found that the scale effect of roughness parameters mainly comes from the sampling methods and the geometric characteristics of parameters.Furthermore,a full data sampling method considering heterogeneity is proposed to obtain more representative roughness parameters.To reveal the scale effect mechanisms of shear strength,Gaussian filtering is firstly used to separate the waviness and unevenness components of roughness,facilitating a deeper understanding of the geometric characteristics of roughness.It is suggested that the wavelength of the waviness component can reflect the scale effect on shear strength.Secondly,numerical simulations of ideal artificial joint models are conducted to validate that the wavelength of the waviness component serves as the dividing point between positive and negative scale effects.The mechanical mechanisms of positive and negative scale effects are also interpreted.Finally,these mechanisms successfully elucidate the occurrence patterns of the scale effect on natural joint profiles. 展开更多
关键词 Rock joint Joint roughness coefficient(JRC) Shear strength Scale effect
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Entropy Consistency-Based Adaptive Sampling Method for Determining the Scale Effect in the Joint Roughness Coefficient 认领 引用
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作者 Jibo Qin Jun Ye +1 位作者 Xiaoming Sun Shigui Du 《Journal of Earth Science》 SCIE CAS CSCD 2025年第2期644-653,共10页
The joint roughness coefficient(JRC) is one of the key parameters for evaluating the shear strength of rock joints.Because of the scale effect in the JRC,reliable JRC values are of great importance for most rock engin... The joint roughness coefficient(JRC) is one of the key parameters for evaluating the shear strength of rock joints.Because of the scale effect in the JRC,reliable JRC values are of great importance for most rock engineering projects.During the collection process of JRC samples,the redundancy or insufficiency of representative rock joint surface topography(RJST) information in serial length JRC samples is the essential reason that affects the reliability of the scale effect results.Therefore,this paper proposes an adaptive sampling method,in which we use the entropy consistency measure Q(a) to evaluate the consistency of the joint morphology information contained in adjacent JRC samples.Then the sampling interval is automatically adjusted according to the threshold Q(at) of the entropy consistency measure to ensure that the degree of change of RJST information between JRC samples is the same,and ultimately makes the representative RJST information in the collected JRC samples more balanced.The application results of actual cases show that the proposed method can obtain the scale effect in the JRC efficiently and reliably. 展开更多
关键词 sampling method joint roughness coefficient(JRC) scale effect entropy consistency measure rock joint engineering geology
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Experimental and numerical investigation on the evolution of Taylor-Quinney coefficient in 42CrMo steel 认领 引用
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作者 Wei Qi Longkang Li +4 位作者 Shengxin Zhu Jianguo Li Manxi Chen Qinglei Zeng Hao-Sen Chen 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第5期239-254,共16页
42CrMo steel was studied in this paper on its thermomechanical behavior when subjected to dynamic compression,utilizing in-situ dynamic tests and crystal plasticity finite element method(CPFEM)simulations.A split Hopk... 42CrMo steel was studied in this paper on its thermomechanical behavior when subjected to dynamic compression,utilizing in-situ dynamic tests and crystal plasticity finite element method(CPFEM)simulations.A split Hopkinson pressure bar,combined with high-speed infrared thermography,was employed to simultaneously record the mechanical response and corresponding temperature evolution,enabling the derivation of the Taylor-Quinney coefficient(TQC).To explore the impact of texture orientation on thermomechanical behavior,a dislocation density-based CPFEM model was applied to analyze the plastic deformation process.The findings demonstrate a satisfactory consistency between numerical predictions and experimental results achieved by the dislocation density-based CPFEM.Simulations of four typical textures demonstrated that texture,through changes in the activated slip systems,significantly influences the evolution of the TQC.These findings contribute valuable insights to the TQC database,enhancing our understanding of material behavior under dynamic loading conditions. 展开更多
关键词 42CrMo Taylor-Quinney coefficient Crystal plasticity Texture effect
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A mesoscale stress-damage-seepage coupling model of hydraulic asphalt concrete incorporating the damage-dependent permeability coefficient of asphalt mortar 认领 引用
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作者 Nanxuan Qian Wei Luo +3 位作者 Bingyu Mei Desheng Yin Yixin Feng Hui Peng 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第1期192-208,共17页
Hydraulic asphalt concrete(HAC)has been increasingly employed as an appropriate impervious structure in hydraulic and hydropower engineering.However,asphalt mortar,usually seen as the matrix of HAC composite,is partic... Hydraulic asphalt concrete(HAC)has been increasingly employed as an appropriate impervious structure in hydraulic and hydropower engineering.However,asphalt mortar,usually seen as the matrix of HAC composite,is particularly prone to damage under combined stress and seepage interactions,and the mesoscale investigations on the damage-seepage coupling behavior of HAC under complex stress states remain limited.This research develops a numerical three-dimensional mesoscale model composed of asphalt mortar and polyhedral aggregate to investigate the stress-damage-seepage coupling behavior in HAC.In this model,asphalt mortar yields the viscoelastic continuum damage law and aggregate obeys the Mazars’elastic-brittle damage law;simultaneously,the effective permeability coefficient of asphalt mortar is assumed to follow an exponential function of damage.The predicted deviatoric stress-strain and hydraulic gradient-seepage curves both are in good agreement with the reported experimental results,which shows the proposed model is valid and reasonable.The simulated results indicate that the damaged asphalt mortar can induce localized areas of high permeability,which in turn affects the overall impervious performance of HAC. 展开更多
关键词 Effective permeability coefficient Viscoelastic continuum damage Stress-seepage coupling
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Effect of bleeding on aerodynamics of non-slender delta wing in ground effect 认领 引用
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作者 Oğuzhan YILMAZ Göktuğ KOÇAK +1 位作者 Murat Kadri AKTAŞ Mehmet Metin YAVUZ 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第5期186-202,共17页
This article experimentally investigates the influence of the passive bleeding technique on the flow structure and aerodynamic coefficients of a non-slender delta wing with a 45-degree sweep angle in Static Ground Eff... This article experimentally investigates the influence of the passive bleeding technique on the flow structure and aerodynamic coefficients of a non-slender delta wing with a 45-degree sweep angle in Static Ground Effect(SGE).The study was conducted under both static and dynamic boundary conditions using a fixed plate and a moving belt,respectively.Particle Image Velocimetry(PIV)and force/moment measurements were performed in a low-speed wind tunnel at Reynolds number,Re=9×104.The results indicate that bleeding in ground effect shifts the focal point toward the leading-edge and increases inboard/outboard vorticity at low angle of attack α=6°,which may enhance the shear-layer feeding mechanism.At high angle of attack α=17°,bleeding in ground effect reduces the adverse effects introduced by the ground proximity,potentially delaying stall.Regarding aerodynamic coefficients,bleeding overall reduces their sensitivity to the ground.In addition,the dynamic boundary condition results in decreased magnitudes of the aerodynamic coefficients and does not negatively affect the stall angle delay provided by the bleeding mechanism,unlike the static boundary condition. 展开更多
关键词 Aerodynamic coefficients Bleed systems Flow control Ground effect Longitudinal stability Stall Static stability
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Finite element method for transient response of viscoelastic multidirectional FGP skew-nanoplate resting on visco-Pasternak foundation taking into account surface effect using nonlocal strain gradient theory 认领 引用
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作者 Thu Huong Nguyen Thi Van Ke Tran +1 位作者 Pham Hoang Tu Pham Hong Thao 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第4期110-135,共26页
The finite element approach is used for the first time to simulate and examine the free oscillation and transient response of a visco-elastic multi-directional functionally graded porous(MFGP)skew-nanoplate,taking int... The finite element approach is used for the first time to simulate and examine the free oscillation and transient response of a visco-elastic multi-directional functionally graded porous(MFGP)skew-nanoplate,taking into account surface effects using nonlocal strain gradient hypothesis.The mechanical characteristics of the materials vary in all three directions of length,width,and thickness of the plate according to the exponential law.Additionally,it has viscoelastic behavior according to the Kelvin-Voigt model.The novelty of this paper lies in the incorporation of the spatial variability of nonlocal and lengthscale factors as additional mechanical characteristics of the material.The overall equation of motion for the plate is derived by including the classical plate hypothesis and Hamilton’s principle.A quadrilateral plate element with four nodes and six degrees of freedom is created using a non-conforming C2-level Hermitian function.This function offers precise results and rapid convergence for various forms and boundary conditions(BCs)that low-order elements cannot accomplish.The Newmark-beta direct integration technique is used to calculate the transient responses of the visco-elastic MFGP skew-nanoplate under various BCs.Furthermore,a thorough assessment of the impacts of several factors such as residual surface stress,grading indices,elastic foundation stiffness,skew angle,other geometrical parameters,and BCs on the transient responses of the viscoelastic MFGP skew-nanoplate has been uncovered. 展开更多
关键词 Nonlocal strain gradient hypothesis Surface effect Finite element method Variable length scale Nonlocal coefficient
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Effects of tooth bending damage on the leakage performance and rotordynamic coefficients of labyrinth seals 认领 引用 被引量：14
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作者 Yaoxing CHEN Zhigang LI +1 位作者 Jun LI Xin YAN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2020年第4期1206-1217,共12页
Tooth bending damage resulting from an intense impact by the rotor sometimes occurs in the transient operation.To investigate the influence of after-damage clearance and tooth bending length on the leakage performance... Tooth bending damage resulting from an intense impact by the rotor sometimes occurs in the transient operation.To investigate the influence of after-damage clearance and tooth bending length on the leakage performance and rotordynamic coefficients of labyrinth seals,three tooth bending damages were taken into consideration,including the unbent tooth damage(abbreviated as Unbent),the partial tooth bending damage(abbreviated as Pbent)and the complete tooth bending damage(abbreviated as Cbent).The transient CFD solution was utilized to calculate the leakage flow rates and rotordynamic coefficients of labyrinth seals with clearances of 0.3,0.4,0.5,0.6 mm for three tooth bending damages.The obtained result shows that the Unbent tooth damage leaks least while the Pbent tooth bending damage leaks most,and an increase of 6.1%for Cbent tooth bending damage and an increase of 19.4%for Pbent tooth bending damage are discovered at the tooth clearance of 0.6 mm in comparison with the Unbent tooth damage.Compared to the Unbent tooth damage,the effective damping for Pbent tooth bending damage and Cbent tooth bending damage is lower and drops by 9.7%–33.6%and 8.5%–22.6%respectively at the tooth clearance of 0.6 mm,suggesting that Pbent tooth bending damage or Cbent tooth bending damage tends to weaken the seal stability when compared to the Unbent tooth damage. 展开更多
关键词 Labyrinth seal Leakage Rotor forward whirl Rotordynamic coefficients Tooth bending damage Vena contracta effect
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Irradiation effect on strain sensitivity coefficient of strain sensing fiber Bragg gratings 认领 引用 被引量：4
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作者 金靖 林松 宋凝芳 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第1期254-259,共6页
The effect of irradiation on the strain sensitivity coefficient of strain sensing fiber Bragg gratings （FBGs） has been investigated through experiments. FBGs were fabricated in single mode fibers with 3 tool% Ge-con... The effect of irradiation on the strain sensitivity coefficient of strain sensing fiber Bragg gratings （FBGs） has been investigated through experiments. FBGs were fabricated in single mode fibers with 3 tool% Ge-concentration in the core and with a H2-1oading treatment. In experiments, the FBGs were subjected to y-radiation exposures using a Co6~ source at a dose-rate of 25 Gy/min up to a total dose of 10.5 kGy. The GeO defect in fiber absorbs photons to form a GeE＇ defect; the interaction with H2 is a probable reason for the y-radiation sensitivity of gratings written in hydrogen loaded fibres, The effect mechanism of radiation on the strain sensitivity coefficient is similar to that of radiation on the temperature sensitivity coefficient. Radiation affects the effective index neff, which results in the change of the thermo-optic coefficient and the strain-optic coefficient. Irradiation can change the strain sensitivity coefficient of FBGs by 1.48%-2.71%, as well as changing the Bragg wavelength shift （BWS） by 22 pm-25 pm under a total dose of 10.5 kGy. Our research demonstrates that the effect of irradiation on the strain sensitivity coefficient of FBG is small and that strain sensing FBGs can work well in the radiation environment. 展开更多
关键词 fiber Bragg grating irradiation effect strain sensitivity coefficient
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The effective ionization coefficients and electron drift velocities in gas mixtures of CF_3I with N_2 and CO_2 obtained from Boltzmann equation analysis 认领 引用 被引量：18
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作者 邓云坤 肖登明 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第3期352-357,共6页
The electron swarm parameters including the density-normalized effective ionization coefficients（α-η）/N and the electron drift velocities V e are calculated for a gas mixture of CF3I with N2 and CO2 by solving the... The electron swarm parameters including the density-normalized effective ionization coefficients（α-η）/N and the electron drift velocities V e are calculated for a gas mixture of CF3I with N2 and CO2 by solving the Boltzmann equation in the condition of a steady-state Townsend（SST） experiment.The overall density-reduced electric field strength is from 100 Td to 1000 Td（1 Td = 10-17V·cm2）,while the CF3I content k in the gas mixture can be varied over the range from 0% to 100%.From the variation of（αη）/N with the CF3I mixture ratio k,the limiting field strength（E/N） lim for each CF3I concentration is derived.It is found that for the mixtures with 70% CF3I,the values of（E/N） lim are essentially the same as that for pure SF 6.Additionally,the global warming potential（GWP） and the liquefaction temperature of the gas mixtures are also taken into account to evaluate the possibility of application in the gas insulation of power equipment. 展开更多
关键词 effective ionization coefficient electron drift velocity insulation characteristics CF3I gas mixtures
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Effect of Temperature on Segregation Coefficients of Impurities in Phosphorus 认领 引用 被引量：2
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作者 刘雪峰 李军 +2 位作者 罗建洪 周堃 杨兆鹏 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2014年第3期294-298,共5页
The present work is focused on the relationship between effective segregation coefficient keff and tem- perature of melting zone for purification of phosphorus by zone melting method. Values of keff at four temperatur... The present work is focused on the relationship between effective segregation coefficient keff and tem- perature of melting zone for purification of phosphorus by zone melting method. Values of keff at four temperatures of melting zone are obtained for zone pass n = 1 at travel velocity of molten zone v = 5x 10^-3 m. h^-1 and initial impu- rity concentration C0〈10 μg.g-1, lnkeff is a linear function of 1/T. The keff values of A1, Ca, Cr, Fe, Cd and Sb in- crease with temperatures while that of Mg is almost constant. The purification is acceptable at lower temperature of melting zone such as 323 K. The variations of enthalpy and entropy between impurities and phosphorus in the liq- uid and solid ohases are also 19resented. 展开更多
关键词 phosphorus purity temperature effective segregation coefficient zone melting
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M-T Scheme for Predicting Effective Diffusion Coefficient of Chloride Ions in Cement-based Materials 认领 引用 被引量：2
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作者 SUN Guowen ZHANG Jianjian +4 位作者 ZHANG Lijuan CAO Tongning WANG Penshuo ZHANG Ying YAN Na 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2020年第3期520-527,共8页
To investigate the transport characteristics of chloride ions in cement-based materials, the Mori-Tanaka (M-T) prediction scheme of the effective diffusion coefficient in composites containing single-phase and multi-p... To investigate the transport characteristics of chloride ions in cement-based materials, the Mori-Tanaka (M-T) prediction scheme of the effective diffusion coefficient in composites containing single-phase and multi-phase inclusions is systematically deduced based on the theory of composite mechanics and porous medium. The volume fraction, morphology and distribution of aggregates, as well as the interfacial transition zone (ITZ) are fully taken into consideration in this proposed model. The results show that the algorithm of M-T prediction scheme with high accuracy is relatively simple. 展开更多
关键词 M-T scheme chloride ion effective diffusion coefficient cement-based materials ITZ
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THEORETICAL MODEL OF EFFECTIVE STRESS COEFFICIENT FOR ROCK/SOIL-LIKE POROUS MATERIALS 认领 引用 被引量：7
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作者 Kai Zhang Hui Zhou +2 位作者 Dawei Hu Yang Zhao Xiating Feng 《Acta Mechanica Solida Sinica》 SCIE EI 2009年第3期251-260,共10页
Physical mechanisms and influencing factors on the effective stress coefficient for rock/soil-like porous materials are investigated,based on which equivalent connectivity index is proposed.The equivalent connectivity... Physical mechanisms and influencing factors on the effective stress coefficient for rock/soil-like porous materials are investigated,based on which equivalent connectivity index is proposed.The equivalent connectivity index,relying on the meso-scale structure of porous material and the property of liquid,denotes the connectivity of pores in Representative Element Area(REA).If the conductivity of the porous material is anisotropic,the equivalent connectivity index is a second order tensor.Based on the basic theories of continuous mechanics and tensor analysis,relationship between area porosity and volumetric porosity of porous materials is deduced.Then a generalized expression,describing the relation between effective stress coefficient tensor and equivalent connectivity tensor of pores,is proposed,and the expression can be applied to isotropic media and also to anisotropic materials.Furthermore,evolution of porosity and equivalent connectivity index of the pore are studied in the strain space,and the method to determine the corresponding functions in expressions above is proposed using genetic algorithm and genetic programming.Two applications show that the results obtained by the method in this paper perfectly agree with the test data.This paper provides an important theoretical support to the coupled hydro-mechanical research. 展开更多
关键词 rock/soil-like porous materials generalized model for effective stress coefficient tensor equivalent connectivity index of pore genetic algorithm
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The influence of reactor core parameters on effective breeding coefficient Keff 认领 引用 被引量：3
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作者 刘立坡 刘义保 +2 位作者 王娟 杨波 张涛 《Chinese Physics B》 SCIE EI CAS 2008年第3期896-900,共5页
The values of effective breeding coefficient Keff in a reactor core of nuclear power plant are calculated for different values of parameters （core structure, fuel assembly component） by using the Monte Carlo method.... The values of effective breeding coefficient Keff in a reactor core of nuclear power plant are calculated for different values of parameters （core structure, fuel assembly component） by using the Monte Carlo method. The obtained values of Keff are compared and analysed, which can provide theoretical basis for reactor design. 展开更多
关键词 Monte Carlo method reactor core parameter effective breeding coefficient Keff
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Preparation of Polyacrylate-based Conductive Coatings and Its PTC Effect 认领 引用 被引量：7
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作者 熊传溪 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2004年第1期26-29,共4页
Polyacrylate-based conductive coatings were prepared from polyacrylate emulsion as matrix and carbon black (CB) whose surface was treated with titanate coupling agent as conducting particles.One kind of organic crysta... Polyacrylate-based conductive coatings were prepared from polyacrylate emulsion as matrix and carbon black (CB) whose surface was treated with titanate coupling agent as conducting particles.One kind of organic crystal was added to study its effects on the electrical conductivity and PTC(positive temperature coefficient)effect of the conductive coatings.Experimental results show that the coatings containing only polyacrylate emulsion and CB exhibit an excellent electrical conductivity but bad PTC effect,and when organic crystal is added,PTC effect is characterized and can increase by 2 orders of magtitude.The critical transformation temperature of polyacrylate emulsion/CB PTC composites is decided by melting point of organic crystals. 展开更多
关键词 carbon block PTC effect organic crystal
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Electron Transport Coefficients and Effective Ionization Coefficients in SF_6-O_2 and SF_6-Air Mixtures Using Boltzmann Analysis 认领 引用 被引量：1
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作者 魏林生 徐敏 +3 位作者 袁定琨 章亚芳 胡兆吉 谭志洪 《Plasma Science and Technology》 SCIE EI CAS CSCD 2014年第10期941-947,共7页
The electron drift velocity, electron energy distribution function （EEDF）, densitynormalized effective ionization coefficient and density-normalized longitudinal diffusion velocity are calculated in SF6-O2 and SFs-A... The electron drift velocity, electron energy distribution function （EEDF）, densitynormalized effective ionization coefficient and density-normalized longitudinal diffusion velocity are calculated in SF6-O2 and SFs-Air mixtures. The experimental results from a pulsed Townsend discharge are plotted for comparison with the numerical results. The reduced field strength varies from 40 Td to 500 Td （1 Townsend=10-17 V.cm2） and the SF6 concentration ranges from 10% to 100%. A Boltzmann equation associated with the two-term spherical harmonic expansion approximation is utilized to gain the swarm parameters in steady-state Townsend. Results show that the accuracy of the Boltzlnann solution with a two-term expansion in calculating the electron drift velocity, electron energy distribution function, and density-normalized effective ionization coefficient is acceptable. The effective ionization coefficient presents a distinct relationship with the SF6 content in the mixtures. Moreover, the E/Ncr values in SF6-Air mixtures are higher than those in SF6-O2 mixtures and the calculated value E/Ncr in SF6-O2 and SF6-Air mixtures is lower than the measured value in SFB-N2. Parametric studies conducted on these parameters using the Boltzmann analysis offer substantial insight into the plasma physics, as well as a basis to explore the ozone generation process. 展开更多
关键词 effective ionization coefficient drift velocity EEDF longitudinal diffusion velocity
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Fractal scaling of effective diffusion coefficient of solute in porous media 认领 引用 被引量：1
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作者 Liu, JG Nie, YF 《Journal of Environmental Sciences》 SCIE EI CAS 2001年第2期170-172,共3页
Fractal approach is used to derive a power law relation between effective diffusion coefficient of solute in porous media and the geometry parameter characterizing the media. The results are consistent with the empiri... Fractal approach is used to derive a power law relation between effective diffusion coefficient of solute in porous media and the geometry parameter characterizing the media. The results are consistent with the empirical equations analogous to Archie`s law and are expected to be applied to prediction of effective diffusion coefficient. Key words: diffusion; effective diffusion coefficient; fractal; porous media. 展开更多
关键词 diffusion effective diffusion coefficient fractal porous media
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Secondary settlement estimation in surcharge preload subject to time effect of secondary consolidation coefficient 认领 引用 被引量：2
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作者 胡亚元 杨平 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第2期341-352,共12页
In order to eliminate the settlement underestimation in surcharge preload engineering, a study based on Bjerrum's creep diagram and the tangent slope definition of secondary consolidation coefficient was carried o... In order to eliminate the settlement underestimation in surcharge preload engineering, a study based on Bjerrum's creep diagram and the tangent slope definition of secondary consolidation coefficient was carried out to analyze the time effect of secondary consolidation coefficient of over consolidated soil, and a time–growth model for it was formulated. As Bjerrum's creep diagram is an idealized model, oedometer tests were performed to improve the above time–growth model of secondary consolidation coefficient for the purpose of achieving a better agreement with the actual ground situations. It is found that secondary consolidation coefficient of over consolidated soil not only decreases with the ratio of historical maximum to current effective stress of soil(OCR), but also increases with the development time of secondary consolidation. No matter how large OCR is, the long-term time effect of secondary consolidation coefficient of over consolidated soil is all significant. Based on the above results, a model for settlement estimation was formulated and a case study to estimate it indicates that the settlement estimated by our method is 2–5 times larger than that estimated by the previous method. Moreover, the larger the OCR is as well as the longer the service life is, the larger the difference between our method and the previous method is. Thus, the post-construction secondary settlement in surcharge preload engineering will be underestimated when neglecting the time effect of secondary consolidation coefficient in over consolidated state. 展开更多
关键词 post-construction secondary settlement time effect tangent slope secondary consolidation coefficient
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A novel three-ring-core few-mode fiber with large effective area and low nonlinear coefficient 认领 引用 被引量：3
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作者 于如愿 郑宏军 +2 位作者 黎昕 白成林 胡卫生 《Optoelectronics Letters》 EI 2018年第1期30-35,共6页
A novel three-ring-core few-mode fiber with large effective area and low nonlinear coefficient is proposed in this paper. The fiber characteristics based on the full-vector finite element method(FEM) with perfect matc... A novel three-ring-core few-mode fiber with large effective area and low nonlinear coefficient is proposed in this paper. The fiber characteristics based on the full-vector finite element method(FEM) with perfect matched layer boundary conditions show that four supermodes with large effective area, low nonlinear coefficient and low differential mode group delay(DMGD) are achieved. With the increase of input wavelength, the effective areas of three-ring-core few-mode fiber are increased, and the nonlinear coefficients are decreased. The bending losses are increased with the increase of input wavelength, and are decreased with the increase of bending radius. Moreover, the proposed fiber performs a nonlinear coefficient and DMGD flattened profile at a large wavelength range. 展开更多
关键词 A novel three-ring-core few-mode fiber with large effective area and low nonlinear coefficient
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A practical formula for penetration depth of rigid projectiles into rock and concrete considering the non-scaling effect 认领 引用 被引量：1
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作者 Xiaohan Zhang Tianhan Xu Zhen Wang 《Defence Technology（防务技术）》 SCIE EI CAS CSCD 2025年第11期98-111,共14页
The non-scaling effect on the penetration depth of rigid projectiles is an important issue that must be considered when extending the results of scaled experiments to prototype scenes.In this study,the evolution of th... The non-scaling effect on the penetration depth of rigid projectiles is an important issue that must be considered when extending the results of scaled experiments to prototype scenes.In this study,the evolution of the stress and strain of the target under penetration was analyzed.Expressions for the penetration resistance and penetration depth were obtained based on the conservation equation and continuity condition of the target.The penetration coefficients that characterize the nose shape,target resistance,and non-scaling effect were defined.Simplified calculation methods for the coefficients within the range of rigid projectile penetration were developed.Two methods for estimating the target parameters are proposed.The results show that the non-scaling effect is related to the failure process of the target and depends on the ratio of cavity radius to comminuted region radius.The nose shape coefficient can be approximated as a linear function of the length-to-diameter ratio of the nose.The noseshape coefficient of a flat-nosed projectile is 0.57.The caliber coefficient is related to the projectile diameter and reflects the non-scaling effect,which increases with the projectile diameter.A practical formula for calculating the penetration depth of rigid projectiles considering the non-scaling effect is also proposed.This formula is in good agreement with penetration experiments on rock and concrete. 展开更多
关键词 Penetration depth Rigid projectile Non-scaling effect Nose shape coefficient Caliber coefficient
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THEORETICAL EFFECTS OF MOLECULAR DIMENSION AND CONFIGURATION ON EFFECTIVE DIFFUSION COEFFICIENT OF MACROMOLECULES IN MICROPOROUS MEMBRANES 认领 引用 被引量：1
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作者 何志敏 《Transactions of Tianjin University》 CAS 1995年第1期47+42-47,共48页
This paper presents a theoretical method for predicting the effective diffusion coefficient of macromolecules in the microporous membrfines in view of the effects of molecular dimension and configuration. On the basis... This paper presents a theoretical method for predicting the effective diffusion coefficient of macromolecules in the microporous membrfines in view of the effects of molecular dimension and configuration. On the basis of the hindered diffusion theory of spherical neutral macromolecules in a micropore of a long cylinder, the effects of molecular dimension and configuration are studied by defining two molecular dimensions:the mean projected radius to predict the concentration partition and the ' hydrodynamically equivalent sphere' radius to evaluate the hydrodynamic reverse drag force. The quantitative comparison shows that the effective diffusion coefficients for different macromolecules predicted by the present method are more consistent with the available published experimental data. 展开更多
关键词 effective diffusion coefficient microporous membrane molecular size molecular configuration
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