期刊文献+
共找到17篇文章
< 1 >
每页显示 20 50 100
Mechanical responses and acoustic emission behaviors of coal under compressive differential cyclic loading(DCL):a numerical study via 3D heterogeneous particle model
1
作者 Zhengyang Song Yunfeng Wu +2 位作者 Yong Zhang Yi Yang Zhen Yang 《International Journal of Coal Science & Technology》 EI CAS CSCD 2023年第3期136-154,共19页
The stability of coal walls(pillars)can be seriously undermined by diverse in-situ dynamic disturbances.Based on a 3D par-ticle model,this work strives to numerically replicate the major mechanical responses and acous... The stability of coal walls(pillars)can be seriously undermined by diverse in-situ dynamic disturbances.Based on a 3D par-ticle model,this work strives to numerically replicate the major mechanical responses and acoustic emission(AE)behaviors of coal samples under multi-stage compressive cyclic loading with different loading and unloading rates,which is termed differential cyclic loading(DCL).A Weibull-distribution-based model with heterogeneous bond strengths is constructed by both considering the stress-strain relations and AE parameters.Six previously loaded samples were respectively grouped to indicate two DCL regimes,the damage mechanisms for the two groups are explicitly characterized via the time-stress-dependent variation of bond size multiplier,and it is found the two regimes correlate with distinct damage patterns,which involves the competition between stiffness hardening and softening.The numerical b-value is calculated based on the mag-nitudes of AE energy,the results show that both stress level and bond radius multiplier can impact the numerical b-value.The proposed numerical model succeeds in replicating the stress-strain relations of lab data as well as the elastic-after effect in DCL tests.The effect of damping on energy dissipation and phase shift in numerical model is summarized. 展开更多
关键词 Differential cyclic loading(DCL) Particle model Acoustic emission(AE) Discrete element method(DEM)Damage mechanism
下载PDF
Formation Mechanism of NiAl/TiB_2 Nanocomposite by Mechanical Alloying Elemental Powders 被引量:1
2
作者 Lanzhang ZHOU and Jianting GUO(Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1998年第6期491-496,共6页
A NiAl/TiB2 nanocomposite is synthesized by mechanical alloying elemental powders. Upon milling for a certain time, an abrupt exothermic reaction occurs and a large amount of NiAl and TiB2 compounds form simultaneousl... A NiAl/TiB2 nanocomposite is synthesized by mechanical alloying elemental powders. Upon milling for a certain time, an abrupt exothermic reaction occurs and a large amount of NiAl and TiB2 compounds form simultaneously. It is suggested that two separate chemical reactions,i.e. Ni+Al →NiAl and Ti+2B→TiB2, are involved during the exothermic reaction. Additionof Ti and B to Ni-Al system impedes the structural evolution of Ni and Al powders and delays the abrupt reaction. The final products are equilibrium phases without any metastable phases formed. This type of reaction is suggested to be suitable for alloy systems with two large heatrelease reactions. 展开更多
关键词 NIAL TIB Formation Mechanism of NiAl/TiB2 Nanocomposite by mechanical Alloying Elemental Powders
下载PDF
Cu Partitioning Behavior and Its Effect on Microstructure and Mechanical Properties of 0.12C-1.33Mn-0.55Cu Q&P Steel 被引量:6
3
作者 陈连生 HU Baojia +4 位作者 XU Jinghui 田亚强 ZHENG Xiaoping SONG Jinying XU Yong 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2017年第5期1179-1185,共7页
Cu, as an austenitic stable element, is added to steel in order to suppress the adverse effects of high content of C and Mn on welding. Based on C partitioning, Cu and Mn partitioning can further improve the stability... Cu, as an austenitic stable element, is added to steel in order to suppress the adverse effects of high content of C and Mn on welding. Based on C partitioning, Cu and Mn partitioning can further improve the stability of retained austenite in the intercritical annealing process. A sample of low carbon steel containing Cu was treated by the intercritical annealing, then quenching process(I&Q). Subsequently, another sample was treated by the intercritical annealing, subsequent austenitizing, then quenching and partitioning process(I&Q&P). The effects of element partitioning behavior in intercritical region on the microstructure and mechanical properties of the steel were studied. The results showed that after the I&Q process ferrite and martensite could be obtained, with C, Cu and Mn enriched in the martensite. When intercritically heated at 800 ℃, Cu and Mn were partitioned from ferrite to austenite, which was enhanced gradually as the heating time was increased. This partitioning effect was the most obvious when the sample was heated at 800 ℃ for 40 min. At the early stage of α→γ transformation, the formation of γ was controlled by the partitioning of carbon, while at the later stage, it was mainly affected by the partitioning of Cu and Mn. After the I&Q&P process, the partitioning effect of Cu and Mn element could be retained. C was assembled in retained austenite during the quenching and partitioning process. The strength and elongation of I&Q&P steel was increased by 5 305 MPa% compared with that subjected to Q&P process. The volume fraction of retained autensite was increased from 8.5% to 11.2%. Hence, the content of retained austenite could be improved significantly by Mn and Cu partitioning, which increased the elongation of steel. 展开更多
关键词 low carbon high strength steel intercritical annealing element partitioning behavior retained austenite mechanical properties
下载PDF
A multiscale 3D finite element analysis of fluid/solute transport in mechanically loaded bone 被引量:4
4
作者 Lixia Fan Shaopeng Pei +1 位作者 X Lucas Lu Liyun Wang 《Bone Research》 SCIE CAS CSCD 2016年第3期154-163,共10页
The transport of fluid, nutrients, and signaling molecules in the bone lacunar-canalicular system (LCS) is critical for osteocyte survival and function. We have applied the fluorescence recovery after photobleaching... The transport of fluid, nutrients, and signaling molecules in the bone lacunar-canalicular system (LCS) is critical for osteocyte survival and function. We have applied the fluorescence recovery after photobleaching (FRAP) approach to quantify load-induced fluid and solute transport in the LCS in situ, but the measurements were limited to cortical regions 30-50 μm underneath the periosteum due to the constrains of laser penetration. With this work, we aimed to expand our understanding of load-induced fluid and solute transport in both trabecular and cortical bone using a multiscaled image-based finite element analysis (FEA) approach. An intact murine tibia was first re-constructed from microCT images into a three-dimensional (3D) linear elastic FEA model, and the matrix deformations at various locations were calculated under axial loading. A segment of the above 3D model was then imported to the biphasic poroelasticity analysis platform (FEBio) to predict load-induced fluid pressure fields, and interstitial solute/fluid flows through LCS in both cortical and trabecular regions. Further, secondary flow effects such as the shear stress and/or drag force acting on osteocytes, the presumed mechano-sensors in bone, were derived using the previously developed ultrastructural model of Brinkman flow in the canaliculi. The material properties assumed in the FEA models were validated against previously obtained strain and FRAP transport data measured on the cortical cortex. Our results demonstrated the feasibility of this computational approach in estimating the fluid flux in the LCS and the cellular stimulation forces (shear and drag forces) for osteocytes in any cortical and trabecular bone locations, allowing further studies of how the activation of osteocytes correlates with in vivo functional bone formation. The study provides a promising platform to reveal potential cellular mechanisms underlying the anabolic power of exercises and physical activities in treating patients with skeletal deficiencies. 展开更多
关键词 A multiscale 3D finite element analysis of fluid/solute transport in mechanically loaded bone FIGURE
下载PDF
STUDY ON THE SEPARATION AND EXTRACTION MECHANISM OF RARE EARTH ELEMENTS BY MEANS OF REVERSED-PHASE PAPER CHROMATOGRAPHY
5
作者 Wang Yingwei Zheng Jianxiang(Department of Chemistry,Xiangtan University,Xiangtan 411105,P.R.China) 《Journal of Rare Earths》 SCIE EI CAS CSCD 1990年第1期15-20,共6页
Reversed-phase paper chromatography technique is used for study on the extraction mechanism and sep- aration of rare earth elements.As the stationary phase,chromatographic paper strips are impregnated with a solution ... Reversed-phase paper chromatography technique is used for study on the extraction mechanism and sep- aration of rare earth elements.As the stationary phase,chromatographic paper strips are impregnated with a solution of monomyristyl phosphoric acid (MPA) in chloroform.Mineral acids are used as developers. The effect of concentration of acids and/or salts upon R_f has been investigated.According to the re- sults of R_f values for a given rare earth element in various acids,the order of extraction ability is HCl>HNO_3>H_2SO_4.A tetrad effect is clearly observed.for the R_f value of rare earth elements.The effects of other parameters on the R_f value,such as the quantities of extractant retained by the paper and the temperature are also examined.Based on the determination of the molar ratio of MPA to rare earth elements and the number of H^+ ions released in extraction reaction,a reasonable mechanism is proposed.The mutual separation of heavy rare earth elements will be better than that of the light rare earth group because of the larger separation coefficient of the former.A mixture of Ho-Er-Tm-Lu is successfully separated by the present method. 展开更多
关键词 than STUDY ON THE SEPARATION AND EXTRACTION MECHANISM OF RARE EARTH elements BY MEANS OF REVERSED-PHASE PAPER CHROMATOGRAPHY Eu HCI MPA
下载PDF
Constitutive model of rock based on microstructures simulation 被引量:3
6
作者 叶洲元 洪亮 +1 位作者 刘希灵 尹土兵 《Journal of Central South University of Technology》 EI 2008年第2期230-236,共7页
The constitutive model of rock can be built by mechanics elements because there are many kinds of damages in rock under varied loads.It is resumed that rock contains many microstructures and a structure of Bingham.The... The constitutive model of rock can be built by mechanics elements because there are many kinds of damages in rock under varied loads.It is resumed that rock contains many microstructures and a structure of Bingham.The microstructure consists of two embranchments that are the unit of a spring and a gliding slice in series and the unit of a spring and a cementation bar in series,the two units connect each other in parallel.These microstructures are arranged disorderly or in the order of a certain state.A certain distribution of microstructures represents one type of rock.Two kinds of rock's constitutive relationship were deduced by using the model.One is the model in which many parallel microstructures and a structure of Bingham connect in series.And it is used to homogeneous rock.The other is the model in which many microstructures and a structure of Bingham connect in series.And it is used to the rock with much crack or microcrack in a certain direction.The two kinds of constitutive relationship were verified by the studied cases.The constitutive model of rock built by using mechanics elements is verified to be reasonable.Moreover,different types of rocks may be described with mechanics elements with different distributions. 展开更多
关键词 constitutive model MICROSTRUCTURE mechanics element connecting type
下载PDF
Influence of intermediate principal stress on failure mechanism of hard rock with a pre-existing circular opening 被引量:5
7
作者 张社荣 孙博 +1 位作者 王超 严磊 《Journal of Central South University》 SCIE EI CAS 2014年第4期1571-1582,共12页
Based on particle flow theory, the influences of the magnitude and direction of the intermediate principal stress on failure mechanism of hard rock with a pre-existing circular opening were studied by carrying out tru... Based on particle flow theory, the influences of the magnitude and direction of the intermediate principal stress on failure mechanism of hard rock with a pre-existing circular opening were studied by carrying out true triaxial tests on siltstone specimen. It is shown that peak strength of siltstone specimen increases firstly and subsequently decreases with the increase of the intermediate principal stress. And its turning point is related to the minimum principal stress and the direction of the intermediate principal stress. Failure characteristic(brittleness or ductility) of siltstone is determined by the minimum principal stress and the difference between the intermediate and minimum principal stress. The intermediate principal stress has a significant effect on the types and distributions of microcracks. The failure modes of the specimen are determined by the magnitude and direction of the intermediate principal stress, and related to weakening effect of the opening and inhibition effect of confining pressure in essence: when weakening effect of the opening is greater than inhibition effect of confining pressure, the failure surface is parallel to the x axis(such as σ2=σ3=0 MPa); conversely, the failure surface is parallel to the z axis(such as σ2=20 MPa, σ3=0 MPa). 展开更多
关键词 rock mechanics intermediate principal stress hard rock with pre-existing circular opening failure mechanism discrete element
下载PDF
Relationship between Rock Fracture Toughness and Physical Properties 被引量:1
8
作者 Zhao Zhenfeng Chen Mian 《Petroleum Science》 SCIE CAS CSCD 2006年第1期56-60,共5页
The relationship between shale toughness and its mechanical parameters is of significance for predicting the shale toughness at a great depth based on the geophysical logging data. A large amount of experiments is per... The relationship between shale toughness and its mechanical parameters is of significance for predicting the shale toughness at a great depth based on the geophysical logging data. A large amount of experiments is performed for toughness measurement of the artificial shale specimens of thick-wall cylinder, with internal pressures applied. Moreover, the finite element method is used to interpret the toughness. The acoustic speeds of the specimens are measured and the relationships between shale toughness and the mechanical parameters, which are almost linear, are established. 展开更多
关键词 Rock toughness physical properties finite element method mechanical
下载PDF
Analysis of Frequency Characteristics and Sensitivity of Compliant Mechanisms 被引量:7
9
作者 LIU Shanzeng DAI Jiansheng +3 位作者 LI Aimin SUN Zhaopeng FENG Shizhe CAO Guohua 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第4期680-693,共14页
Based on a modified pseudo-rigid-body model,the frequency characteristics and sensitivity of the large-deformation compliant mechanism are studied.Firstly,the pseudo-rigid-body model under the static and kinetic condi... Based on a modified pseudo-rigid-body model,the frequency characteristics and sensitivity of the large-deformation compliant mechanism are studied.Firstly,the pseudo-rigid-body model under the static and kinetic conditions is modified to enable the modified pseudo-rigid-body model to be more suitable for the dynamic analysis of the compliant mechanism.Subsequently,based on the modified pseudo-rigid-body model,the dynamic equations of the ordinary compliant four-bar mechanism are established using the analytical mechanics.Finally,in combination with the finite element analysis software ANSYS,the frequency characteristics and sensitivity of the compliant mechanism are analyzed by taking the compliant parallel-guiding mechanism and the compliant bistable mechanism as examples.From the simulation results,the dynamic characteristics of compliant mechanism are relatively sensitive to the structure size,section parameter,and characteristic parameter of material on mechanisms.The results could provide great theoretical significance and application values for the structural optimization of compliant mechanisms,the improvement of their dynamic properties and the expansion of their application range. 展开更多
关键词 compliant mechanism pseudo-rigid-body model frequency characteristic sensitivity analysis finite element analysis
下载PDF
Numerical modelling of nonlinear extreme waves in presence of wind 被引量:1
10
作者 NING Dezhi DU Jun +2 位作者 BAI Wei ZHANG Chongwei TENG Bin 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2018年第9期90-98,共9页
A numerical wave flume with fully nonlinear free surface boundary conditions is adopted to investigate the temporal characteristics of extreme waves in the presence of wind at various speeds. Incident wave trains are ... A numerical wave flume with fully nonlinear free surface boundary conditions is adopted to investigate the temporal characteristics of extreme waves in the presence of wind at various speeds. Incident wave trains are numerically generated by a piston-type wave maker, and the wind-excited pressure is introduced into dynamic boundary conditions using a pressure distribution over steep crests, as defined by Jeffreys' sheltering mechanism.A boundary value problem is solved by a higher-order boundary element method(HOBEM) and a mixed Eulerian-Lagrangian time marching scheme. The proposed model is validated through comparison with published experimental data from a focused wave group. The influence of wind on extreme wave properties,including maximum extreme wave crest, focal position shift, and spectrum evolution, is also studied. To consider the effects of the wind-driven currents on a wave evolution, the simulations assume a uniform current over varying water depth. The results show that wind causes weak increases in the extreme wave crest, and makes the nonlinear energy transfer non-reversible in the focusing and defocusing processes. The numerical results also provide a comparison to demonstrate the shifts at focal points, considering the combined effects of the winds and the wind-driven currents. 展开更多
关键词 extreme waves fully nonlinear numerical wave flume higher-order boundary element wave focusing Jeffreys' sheltering mechanism
下载PDF
Solution set on the natural satellite formation orbits under first-order earth's non-spherical perturbation 被引量:1
11
作者 Humei Wang Wei Yang Junfeng Li 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2005年第5期503-510,共8页
Using the reference orbital element approach, the precise governing equations for the relative motion of formation flight are formulated. A number of ideal formations with respect to an elliptic orbit can be designed ... Using the reference orbital element approach, the precise governing equations for the relative motion of formation flight are formulated. A number of ideal formations with respect to an elliptic orbit can be designed based on the relative motion analysis from the equations. The features of the oscillating reference orbital elements are studied by using the perturbation theory. The changes in the relative orbit under perturbation are divided into three categories, termed scale enlargement, drift and distortion respectively. By properly choosing the initial mean orbital elements for the leader and follower satellites, the deviations from originally regular formation orbit caused by the perturbation can be suppressed. Thereby the natural formation is set up. It behaves either like non-disturbed or need little control to maintain. The presented reference orbital element approach highlights the kinematics properties of the relative motion and is convenient to incorporate the results of perturbation analysis on orbital elements. This method of formation design has advantages over other methods in seeking natural formation and in initializing formation. 展开更多
关键词 Orbital mechanics . Satellite formation flight .Orbital elements . Reference orbital elements . Perturbation
下载PDF
An Average Failure Index Method for the Tensile Strength Prediction of Composite Adhesive-bonded π Joints
12
作者 张建宇 SHAN Meijuan +1 位作者 赵丽滨 FEI Binjun 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第2期292-301,共10页
An average failure index method based on accurate FEA was proposed for the tensile strength prediction of composite out-of-plane adhesive-bonded π joints. Based on the simple and independent maximum stress failure cr... An average failure index method based on accurate FEA was proposed for the tensile strength prediction of composite out-of-plane adhesive-bonded π joints. Based on the simple and independent maximum stress failure criterion, the failure index was introduced to characterize the degree of stress components close to their corresponding material strength. With a brief load transfer analysis, the weak fillers were prominent and further detailed discussion was performed. The maximum value among the average failure indices which were related with different stress components was filtrated to represent the failure strength of the critical surface, which is either the two curved upside surfaces or the bottom plane of the fillers for composite π joints. The tensile strength of three kinds of π joints with different material systems, configurations and lay-ups was predicted by the proposed method and corresponding experiments were conducted. Good agreements between the numerical and experimental results give evidence of the effectiveness of the proposed method. In contrast to the existed time-consuming strength prediction methods, the proposed method provides a capability of quickly assessing the failure of complex out-of-plane joints and is easy and convenient to be widely utilized in engineering. 展开更多
关键词 joints mechanical properties finite element analysis strength
下载PDF
Observation of selective surface element substitution in FeTe_(0.5)Se_(0.5) superconductor thin film exposed to ambient air by synchrotron radiation spectroscopy
13
作者 张念 刘晨 +7 位作者 赵佳丽 雷涛 王嘉鸥 钱海杰 吴蕊 颜雷 郭海中 奎热西 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第9期540-545,共6页
A systematic investigation of oxidation on a superconductive Fe Te_(0.5)Se_(0.5)thin film,which was grown on Nb-doped SrTiO_3(001) by pulsed laser deposition,has been carried out.The sample was exposed to ambien... A systematic investigation of oxidation on a superconductive Fe Te_(0.5)Se_(0.5)thin film,which was grown on Nb-doped SrTiO_3(001) by pulsed laser deposition,has been carried out.The sample was exposed to ambient air for one month for oxidation.Macroscopically,the exposed specimen lost its superconductivity due to oxidation.The specimen was subjected to in situ synchrotron radiation photoelectron spectroscopy(PES) and x-ray absorption spectroscopy(XAS) measurements following cycles of annealing and argon ion etching treatments to unravel what happened in the electronic structure and composition after exposure to air.By the spectroscopic measurements,we found that the as-grown FeTe_(0.5)Se_(0.5)superconductive thin film experienced an element selective substitution reaction.The oxidation preferentially proceeds through pumping out the Te and forming Fe–O bonds by O substitution of Te.In addition,our results certify that in situ vacuum annealing and low-energy argon ion etching methods combined with spectroscopy are suitable for depth element and valence analysis of layered structure superconductor materials. 展开更多
关键词 11 iron-based superconductor oxidation mechanism in ambient air selective surface element substitution synchrotron radiation spectroscopy
下载PDF
Improving the Hydromechanical Deep-Drawing Process Using Aluminum Tailored Heat Treated Blanks
14
作者 Antonio Piccininni Gabriella Di Michele +2 位作者 Gianfranco Palumbo Donato Sorgente Luigi Tricarico 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2015年第12期1482-1489,共8页
The present work demonstrates the effectiveness of combining the hydromechanical deep-drawing process with the Tailored Heat Treated Blank(THTB) technique. In the hydromechanical deep-drawing process, the fluid pres... The present work demonstrates the effectiveness of combining the hydromechanical deep-drawing process with the Tailored Heat Treated Blank(THTB) technique. In the hydromechanical deep-drawing process, the fluid pressure is used for postponing the fracture occurrence in the blank, while the THTB technique allows to create a material property gradient through a suitable artificial aging treatment carried out prior to the forming process. Since the number of process variables is large, in the present work the authors propose an optimization loop for the determination of the parameters controlling the extension of the blank regions to be subjected to the aging treatment and the temperature levels to be set during the heat treatment. The proposed methodology couples a simple finite element model(Abaqus) with a multiobjective optimization platform(mode FRONTIER). A preliminary experimental campaign was carried out for determining the effect of the aging treatment on the mechanical(through tensile tests) and deformative(through formability tests)behavior of the AC170 PX aluminum alloy. Optimization results prove the effectiveness of the adopted methodology and put in evidence that the adoption of properly aged blanks in the hydromechanical deep drawing allows to increase the limit drawing ratio and to simplify the process since it is conducted at room temperature. 展开更多
关键词 Aluminum alloy Aging Hydromechanical deep drawing Finite element analysis mechanical characterization Formability
原文传递
A Review on Casting Magnesium Alloys: Modification of Commercial Alloys and Development of New Alloys 被引量:91
15
作者 Fusheng Pan Mingbo Yang Xianhua Chen 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2016年第12期1211-1221,共11页
The research and development status of casting magnesium alloys including the commercial casting alloys and the new types casting alloys are reviewed,with more attention to microstructure and mechanical properties of ... The research and development status of casting magnesium alloys including the commercial casting alloys and the new types casting alloys are reviewed,with more attention to microstructure and mechanical properties of modified-AZ91,AM60 and WE43 alloys with various additions,and new types of low cost casting alloys and high strength casting alloys.The modification and/or refinement of Mg2 Si phase in Mg-Al-Si based casting alloys by various additions are discussed and new purifying technologies for casting magnesium alloys are introduced to improve the performance.The modified AZ81 alloy with reduced impurities is found to have the tensile strength of 280 ± 6 MPa and elongation of 16% ± 0.7%.The fatigue strength of AZ91 D alloy could be obviously improved by addition of Ce and Nd.The Mg-16Gd-2Ag-0.3Zr alloy exhibits very high tensile and yield strengths(UTS:423 MPa and YS:328 MPa);however,its elongation still needs to be improved. 展开更多
关键词 Casting magnesium alloys Microstructure mechanical properties Corrosion Purification Alloying elements
原文传递
Superior Properties of Mg–4Y–3RE–Zr Alloy Prepared by Powder Metallurgy 被引量:8
16
作者 Jirí Kubásek Drahomír Dvorsky +3 位作者 Miroslav Cavojsky Dalibor Vojtěch Nad'a Beronská Michaela Fousová 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2017年第7期652-660,共9页
Magnesium alloys are important materials for application in the automotive and aviation industries. During the last few years, the number of possible applications as biodegradable implants in medicine has grown. Mg-RE... Magnesium alloys are important materials for application in the automotive and aviation industries. During the last few years, the number of possible applications as biodegradable implants in medicine has grown. Mg-RE(rare earth) alloys belong to the most advanced group of products, offering the best combination of mechanical properties and corrosion resistance. Among these materials, WE43(Mg-Y-Nd)is a very well-known commercial alloy that has been extensively studied for applications at increased temperatures and also in organisms. Although this material has been described, there are still possibilities to improve its properties and subsequently expand its applicability. Powder metallurgy has already been used for the preparation of magnesium alloys with superior mechanical properties and occasionally superior corrosion properties. Therefore, the present paper is oriented toward the preparation of Mg-4Y-3RE-Zr(WE43) alloy by the powder metallurgy technique(WE43-PM) and comparison of the final properties with the product of extrusion of as-cast ingot(WE43-IM). Our processing leads to a partial improvement in the mechanical properties and superior corrosion resistance of WE43-PM. The texture strength of WE43-PM was low, and therefore, anisotropy of mechanical properties was suppressed. 展开更多
关键词 Magnesium alloys REEs(rare earth elements Powder metallurgy mechanical properties Corrosion
原文传递
Continuum damage mechanics based modeling progressive failure of woven-fabric composite laminate under low velocity impact 被引量:4
17
作者 Zhi-gang HU Yan ZHANG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2010年第3期151-164,共14页
A continuum damage mechanics (CDM) meso-model was derived for both intraply and interply progressive failure behaviors of a 2D woven-fabric composite laminate under a transversely low velocity impact.An in-plane aniso... A continuum damage mechanics (CDM) meso-model was derived for both intraply and interply progressive failure behaviors of a 2D woven-fabric composite laminate under a transversely low velocity impact.An in-plane anisotropic damage constitutive model of a 2D woven composite ply was derived based on CDM within a thermodynamic framework,an elastic constitutive model with damage for the fibre directions and an elastic-plastic constitutive model with damage for the shear direction.The progressive failure behavior of a 2D woven composite ply is determined by the damage internal variables in different directions with appropriate damage evolution equations.The interface between two adjacent 2D woven composite plies with different ply orientations was modeled by a traction-separation law based interface element.An isotropic damage constitutive law with CDM properties was used for the interface element,and a damage surface which combines stress and fracture mechanics failure criteria was employed to derive the damage initiation and evolution for the mixed-mode delamination of the interface elements.Numerical analysis and experiments were both carried out on a 2D woven glass fibre/epoxy laminate.The simulation results are in agreement with the experimental counterparts,verifying the progressive failure model of a woven composite laminate.The proposed model will enhance the understanding of dynamic deformation and progressive failure behavior of composite laminate structures in the low velocity impact process. 展开更多
关键词 Continuum damage mechanics (CDM) Woven composite laminate Low velocity impact Interface element Cohesive zone
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部