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elastic modulus OF HUMAN CEMENTUM

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Applied Mathematics and Mechanics(English Edition) 1999年第10期20卷 1134-1141页

作者：叶德临倪海鹰龚一康陈星 SichuanUniv BiomechResLabChengdu610065PeoplesRChina SichuanUniv DeptPlastEngnChengdu610065PeoplesRChina FourthPeoplesHospChengdu Chengdu610036PeoplesRChina SecondPeoplesHospChengdu Chengdu610017PeoplesRChina

In this paper, the elastic modulus measuring of human cementum is studied. The average value of the elastic modulus measured from 100 specimens is E = 2.398 +/- 0.455 GPa. The specimens were made from incisors, canines, bicuspids, and molars. The testing was done on type AG-10TA electronic-mechanical universal material testing machine. It was verified by mathematical statistics that the probability distribution of measured data obeys normal distribution. By the great difference in elastic moduli between cementum and dentin it is explained that 1. why more cementum grows at the root apexes; 2. the behavior of cementum must be taken into consideration when the stress analysis for teeth is carried out.

关键词： human cementum elastic modulus normal distribution

elastic modulus of 304 Stainless Steel Coating by Cold Gas Dynamic Spraying

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Journal of Iron and Steel Research International 2012年第3期19卷 73-78页

作者： HAN Wei1, MENG Xian-ming1, ZHANG Jun-bao2, ZHAO Jie1 (1. School of Material Science and Engineering, Dalian University of Technology, Dalian 116085, Liaoning, China 2. Baoshan Iron and Steel Company Limited, Baosteel Research Institute, Shanghai 201900, China) School of Material Science and Engineering Dalian University of Technology Dalian Liaoning China Baoshan Iron and Steel Company Limited Baosteel Research Institute Shanghai China

304 stainless steel coating was deposited on the IF steel substrate by cold gas dynamic spraying （CGDS）, and the elastic modulus of the 304 stainless steel coating was studied. The elastic modulus of cold sprayed 304 stain- less steel coating was measured using the three-point bend testing and the compound beam theory, and the other me- chanic parameters （such as the equivalent flexural rigidity and the moment of inertia of area） of the coatings were also calculated using this compound beam theory. It is found that the calculated results using the above methods are accu- rate and reliable. The elastic modulus value of the cold sprayed 304 stainless steel coating is 1. 179 X 105 MPa, and it is slightly lower than the 304 stainless steel plate （about 2 X 105 MPa）. It indicates that the elastic modulus of the cold sprayed coatings was quite different from the comparable bulk materials. The main reason is that the pores and other defects are existed in the coatings, and the elastic modulus of the coatings also depends on varies parameters such as the feed stock particle size, porosity, and processing parameters.

关键词： cold gas dynamic spraying 304 stainless steel coating three-point bend testing compound beam theory elastic modulus

elastic modulus Prediction of Three-dimension-4 Directional Braided C_f/SiC Composite Based on Double-scale Model

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Journal of Wuhan University of Technology(Materials Science) 2015年第3期30卷 500-508页

作者：牛序铭 SUN Zhigang KONG Chunyuan 宋迎东 Jiangsu Province Key Laboratory of Aerospace Power System College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics State Key Laboratory of Mechanics and Control Mechanical Structures College of Energy and Power Nanjing University of Aeronautics & Astronautics

Double-scale model for three-dimension-4 directional（3D-4d） braided C/SiC composites has been proposed to investigate its elastic properties. The double-scale model involves micro-scale that takes fiber/ matrix/porosity in fibers tows into consideration with unit cell which considers the 3D-4d braiding structure. Micro-optical photographs of composites have been taken to study the braided structure. Then a parameterized finite element model that reflects the structure of 3D-4d braided composites is proposed. Double-scale elastic modulus prediction model is developed to predict the elastic properties of 3D-4d braided C/SiC composites. Stiffness and eompliance-averaging method and energy method are adopted to predict the elastic properties of composites. Static-tension experiments have been conducted to investigate the elastic modulus of 3D-4d braided C/SiC composites. Finally, the effect of micro-porosity in fibers tows on the elastic modulus of 3D-4d braided C/SiC composites has been studied. According to the conclusion of this thesis, elastic modulus predicted by energy method and stiffness-averaging method both find good agreement with the experimental values, when taking the micro-porosity in fibers tows into consideration. Differences between the theoretical and experimental values become smaller.

关键词： 3D-4d braided C/SiC composites double-scale model elastic modulus energy methodstiffness and compliance-averaging method porosity ratio

elastic modulus affects the growth and differentiation of neural stem cells

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Neural Regeneration Research 2015年第9期10卷 1523-1527页

作者： Xian-feng Jiang Kai Yang Xiao-qing Yang Ying-fu Liu Yuan-chi Cheng Xu-yi Chen Yue Tu Affiliated Hospital of Logistics University of People’s Armed Police Force Liaoning Medical University Logistics University of People’s Armed Police Force

It remains poorly understood if carrier hardness, elastic modulus, and contact area affect neural stem cell growth and differentiation. Tensile tests show that the elastic moduli of Tiansu and SMI silicone membranes are lower than that of an ordinary dish, while the elastic modulus of SMI silicone membrane is lower than that of Tiansu silicone membrane. Neural stem cells from the cerebral cortex of embryonic day 16 Sprague-Dawley rats were seeded onto ordinary dishes as well as Tiansu silicone membrane and SMI silicone membrane. Light microscopy showed that neural stem cells on all three carriers show improved adherence. After 7 days of differentiation, neuron specific enolase, glial fibrillary acidic protein, and myelin basic protein expression was detected by immunofluorescence. Moreover, flow cytometry revealed a higher rate of neural stem cell differentiation into astrocytes on Tiansu and SMI silicone membranes than on the ordinary dish, which was also higher on the SMI than the Tiansu silicone membrane. These findings con- firm that all three cell carrier types have good biocompatibility, while SMI and Tiansu silicone membranes exhibit good mechanical homogenization. Thus, elastic modulus affects neural stem cell differentiation into various nerve cells. Within a certain range, a smaller elastic modulus re- sults in a more obvious trend of cell differentiation into astrocytes.

关键词： nerve regeneration neural stem cells carrier mechanical properties elastic modulus cell differentiation neurons immunofluorescence astrocytes neural regeneration

elastic modulus of claystone evaluated by nano-/micro-indentation tests and meso-compression tests

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第1期9卷 84-91页

作者： Christophe Auvray Noémie Lafrance Danièle Bartier Université de Lorraine CNRS CREGU Lab. GeoRessources UMR 7359 Vandoeuvre-lès-Nancy F-54518 France

Toarcian claystone such as that of the Callovo-Oxfordian is a qualified multiphase material. The claystone samples tested in this study are composed of four main mineral phases: silicates(clay minerals, quartz,feldspars, micas)(z86%), sulphides(pyrite)(z3%), carbonates(calcite, dolomite)(z10%) and organic kerogen(z1%). Three sets of measurements of the modulus of deformability were compared as determined in(i) nanoindentation tests with a constant indentation depth of 2 mm,(ii) micro-indentation tests with a constant indentation depth of 20 mm, and(iii) meso-compression tests with a constant displacement of 200 mm. These three experimental methods have already been validated in earlier studies. The main objective of this study is to demonstrate the influence of the scaling effect on the modulus of deformability of the material. Different frequency distributions of the modulus of deformability were obtained at the different sample scales:(i) in nano-indentation tests, the distribution was spread between 15 GPa and 90 GPa and contained one peak at34 GPa and another at 51 GPa;(ii) in the micro-indentation tests, the distribution was spread between 25 GPa and 60 GPa and displayed peaks at 26 GPa and 37 GPa; and(iii) in the meso-compression tests, a narrow frequency distribution was obtained, ranging from 25 GPa to 50 GPa and with a maximum at around 35 GPa.

关键词： Claystone elastic modulus Scaling effect Nano-and micro-indentation Meso-compression tests Multi-scale mechanical tests

Strength and elastic modulus enhancement in Mg-Li-Al matrix composites reinforced by ex situ TiB2 particles via stir casting

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Journal of Magnesium and Alloys 2024年第9期12卷 3574-3588页

作者： Jiawei Sun Dehua Ding Wencai Liu Guohua Wu Hongjie Liu Guangling Wei Hezhou Liu National Engineering Research Center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

A novel Mg^(-1)0Li-3Al(wt.%,LA103)matrix composite reinforced by ex situ micron TiB_(2) particles was developed in the present *** ball milling and cold pressing pretreatment of the reinforcements made it feasible to prepare this material under stir casting conditions with good *** microstructure and mechanical properties of the composites prepared by different pretreatment methods were analyzed in *** TiB_(2) particles in the Al-TiB_(2)/LA103 composite using the pretreatment process were uniformly distributed in the microstructure due to the formation of highly wettable core-shell units in the *** with the matrix alloys,the Al-TiB_(2)/LA103 composite exhibited effective strength and elastic modulus improvements while maintaining acceptable *** strengthening effect in the composites was mainly attributed to the strong grain refining effect of *** work shows a balance of high specific modulus(36.1 GPa·cm^(3)·g^(-1))and elongation(8.4%)with the conventional stir casting path,which is of considerable application value.

关键词： Mg-Li composite Stir casting elastic modulus Microstructure Mechanical properties

SIZE EFFECTS OF elastic modulus OF FCC METALS BASED ON THE CAUCHY-BORN RULE AND NANOPLATE MODELS

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Acta Mechanica Solida Sinica 2014年第2期27卷 111-121页

作者： Jianyun Liu Jingru Song Yueguang Wei State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences

In the present research, a simple quasi-continuum model, the Cauchy-Born rule model, is used to investigate the size effects of elastic modulus for fcc metals. By considering a nanoplate model and calculating the strain energy for the nano-sized plate under tension and bending, the relationship between the elastic modulus and the plate thickness is found. Size effects of the elastic modulus are displayed by the relative differences of the elastic modulus between the nano-sized plate sample and the bulk sample. By comparing the present results with those of others, the effectiveness of the Cauchy-Born rule model in studying the size effects of material properties are shown.

关键词： quasi-continuum method Cauchy-Born rule size effect elastic modulus fcc-metal

The influence of spark plasma sintering temperatures on the microstructure,hardness,and elastic modulus of the nanocrystalline Al-xV alloys produced by high-energy ball milling

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Journal of Materials Science & Technology 2022年第27期122卷 68-76页

作者： J.Christudasjustus C.S.Witharamage Ganesh Walunj T.Borkar R.K.Gupta Department of Materials Science and Engineering North Carolina State UniversityRaleighNC 27606United States Department of Mechanical Engineering Cleveland State UniversityClevelandOH 44115United States

Al-xV alloys(x=2 at.%,5 at.%,10 at.%)with nanocrystalline structure and high solid solubility of V were produced in powder form by high-energy ball milling(HEBM).The alloy powders were consolidated by spark plasma sintering(SPS)employing a wide range of temperatures ranging from 200 to 400°*** microstructure and solid solubility of V in Al were investigated using X-ray diffraction analysis,scanning electron microscope and transmission electron *** microstructure was influenced by the SPS temperature and V content of the *** alloys exhibited high solid solubility of V–six orders of magnitude higher than that in equilibrium state and grain sizeelastic modulus,measured using nanoindentation,were significantly higher than commercial *** example,Al-V alloy produced by SPS at 200℃ exhibited a hardness of 5.21 GPa along with elastic modulus of 96.21 *** evolution of the microstructure and hardness with SPS temperatures has been discussed.

关键词： Spark plasma sintering Aluminum alloys Nanocrystalline alloys High-energy ball milling Nanoindentation Hardness elastic modulus

Size effect of the elastic modulus of rectangular nanobeams:Surface elasticity effect

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Chinese Physics B 2013年第10期22卷 424-428页

作者：姚海燕云国宏范文亮 College of Ordos Inner Mongolia University Inner Mongolia Key Laboratory of Nanoscience and Nanotechnology College of Physical Science and Technology Inner Mongolia University College of Physics and Electronic Information Inner Mongolia Normal University

The size-dependent elastic property of rectangular nanobeams （nanowires or nanoplates） induced by the surface elas- ticity effect is investigated by using a developed modified core-shell model. The effect of surface elasticity on the elastic modulus of nanobeams can be characterized by two surface related parameters, i.e., inhomogeneous degree constant and surface layer thickness. The analytical results show that the elastic modulus of the rectangular nanobeam exhibits a distinct size effect when its characteristic size reduces below 1 O0 nm. It is also found that the theoretical results calculated by a mod- ified core-shell model have more obvious advantages than those by other models （core-shell model and core-surface model） by comparing them with relevant experimental measurements and computational results, especially when the dimensions of nanostructures reduce to a few tens of nanometers.

关键词： size effects elastic modulus nanobeams surface elasticity