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Subloading-elastoplastic constitutive equation of glass

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Journal of Materials Science & Technology 2024年第18期185卷 221-232页

作者： Koichi Hashiguchi Hiroki Yamazki Shingo Nakane Yoshinari Kato Gustavo Rosales-Sosa Masami Ueno Institute of Advanced Study of Mathematical Sciences Meiji University(Emeritus Professor of Kyushu University)1002136-chomeKuromonFukuoka 810-0055Japan Fundamental Technology Division Nippon Electric Glass Co.Ltd.2-7-1SeiranOtsuShiga 520-8639Japan Emeritus Professor of University of the Ryukyus 1SembaruNishihara-ChoNakagami-GunOkinawa 903-0213Japan

Elastoplastic constitutive equation of glass is proposed in this article,which is formulated based on the subloading surface model which possesses the various distinguished advantages for the description of the plastic deformation,i.e.,the smooth elastic-plastic transition,the continuous variation of the tangent stiff-ness modulus tensor,the automatic controlling function to attract the stress to the yield surface during the plastic deformation process,*** would be the firstly proposed three-dimensional elastoplastic con-stitutive equation of glass,which is furnished with the basic properties,*** ellipsoidal yield surface with the dependence of the third deviatoric stress invariant,undergoing the flattering to the deviatoric direction with the plastic compression and the plastic volumetric hardening with the associated flow *** validity of the description of the deformation behavior of glass will be verified by comparisons with some test data for silica glass specimens.

关键词： Glass Constitutive equation Elasticity Plasticity yield surface Densification Deviatoric deformation

A MICROMECHANICAL MODEL FOR γ-TiAl BASE PST CRYSTALS

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Acta Metallurgica Sinica(English Letters) 2005年第6期18卷 686-694页

作者： J.L. Su G.K. Hu School of Mechanics-Electrics Engineering Fujian Agriculture and Forestry University Fuzhou 350002 China Department of Applied Mechanics Beijing Institute of Technology Beijing 100081 China

An analytical micromechanical method is proposed to examine the dependence of plastic deformation on the microstructure for a PST crystal. The sub-domain microstructure of the γ phase and the effect of the α2 phase are taken into account by a proper micromechanical formulation, the dislocation slip and twinning deformation mechanisms are considered in the context of crystal plasticity. The model can well predict the dependence of stress-strain relations on loading angle with respect to the microstructure. The influence of the twinning and lamellar spacing on the deformation behavior and biaxial yield surfaces for PST crystals are also examined.

关键词： TiAI alloy crystal plasticity micromechanical model yield surface

PLASTIC ZONE OF SEMI-INFINITE CRACK IN PLANAR KAGOME AND TRIANGULAR LATTICES

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Acta Mechanica Solida Sinica 2009年第3期22卷 213-225页

作者： Xinming Qiu Lianghong He Yueqiang Qian Xiong Zhang Department of Engineering Mechanics Tsinghua University Beijing 100084 China

The fracture investigations of the planar lattices made of ductile cell walls are currently limited to bending-dominated hexagonal honeycomb. In this paper, the plastic zones of stretching-dominated lattices, including Kagome and triangular lattices, are estimated by analyzing their effective yield loci. The normalized in-plane yield loci of these two lattices are almost identical convex curves enclosed by 4 straight lines, which is almost independent of the relative density but is highly sensitive to the principal stress directions. Therefore, the plastic zones around the crack tip of Kagome and triangular are estimated to be quite different to those of the continuum solid and also hexagonal lattice. The plastic zones predictions by convex yield surfaces of both lattices are validated by FE calculations, although the shear lag region caused by non-local bending effect in the Kagome lattice enlarges the plastic zone in cases of small ratio of rp/l.

关键词： lattice yield surface crack tip plastic zone anisotropic

AN EQUIVALENT CONTINUUM METHOD OF LATTICE STRUCTURES

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Acta Mechanica Solida Sinica 2006年第2期19卷 103-113页

作者： Fan Hualin Yang Wei Department of Engineering Mechanics Tsinghua University Beijing 100084 China

An equivalent continuum method is developed to analyze the effective stiffness of three-dimensional stretching dominated lattice materials. The strength and three-dimensional plastic yield surfaces are calculated for the equivalent continuum. A yielding model is formulated and compared with the results of other models. The bedding-in effect is considered to include the compliance of the lattice joints. The predicted stiffness and strength are in good agreement with the experimental data, validating the present model in the prediction of the mechanical properties of stretching dominated lattice structures.

关键词： stretching dominated lattice materials equivalent continuum method effective stiffness yield surface bedding-in effect

Review of collapse triggering mechanism of collapsible soils due towetting

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Journal of Rock Mechanics and Geotechnical Engineering 2016年第2期8卷 256-274页

作者： Ping Li Sai Vanapalli Tonglu Li Department of Civil Engineering University of OttawaOttawaONK1N6N5Canada School of Geological Engineering and Geomatics Chang’an UniversityXi’anShaanxi710054China

Loess soil deposits are widely distributed in arid and semi-arid regions and constitute about 10% of land area of the *** soils typically have a loose honeycomb-type meta-stable structure that is susceptible to a large reduction in total volume or collapse upon *** characteristics contribute to various problems to infrastructures that are constructed on loess *** this reason,collapse triggering mechanism for loess soils has been of significant interest for researchers and practitioners all over the *** paper aims at providing a state-of-the-art review on collapse mechanism with special reference to loess soil *** collapse mechanism studies are summarized under three different categories,*** approaches,microstructure approach,and soil mechanics-based *** traditional and microstructure approaches for interpreting the collapse behavior are comprehensively summarized and critically reviewed based on the experimental results from the *** soil mechanics-based approaches proposed based on the experimental results of both compacted soils and natural loess soils are reviewed highlighting their strengths and limitations for estimating the collapse *** soil mechanics-based approaches with less parameters or parameters that are easy-to-determine from conventional tests are suggested for future research to better understand the collapse behavior of natural loess *** studies would be more valuable for use in conventional geotechnical engineering practice applications.

关键词： Collapse mechanism Microstructure Constitutive relationships Compacted soils Natural loess soils Elastoplastic models yield surface Structural strength

Several basic problems in plastic theory of geomaterials

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Frontiers of Structural and Civil Engineering 2009年第1期3卷 81-84页

作者： Yuanxue LIU Jiawu ZHOU Zhongyou LI Chen CHEN Yingren ZHENG The Institute of Geotechnical Engineering Department of Architecture and Civil EngineeringLogistical Engineering UniversityChongqing 400041China

Based on the basic mechanical properties of geomaterials,it was proven that the Drucker Postulate and the classical theory of plasticity can not be applied to ***,several basic problems of plastic theory of geomaterials were *** on the strict theoretical analysis,the following have been proven:the single yield surface model based on the classical theory of plasticity is unsuitable for geomaterials whether the rule of associated flow is applied or not;the yield surface of geomaterials is not unique,and its number is the same as the freedoms of plastic strain increment;the yield surface is not convex;and the rule of associated flow is unsuitable for geomaterials.

关键词： constitutive relation geomaterials classial plastic theory Drucker Postulate yield surface flow rule

Biaxial mechanical behavior of closed-cell aluminum foam under combined shear-compression loading

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Transactions of Nonferrous Metals Society of China 2020年第1期30卷 41-50页

作者： Zhi-bin LI Xue-yan LI Yu-xuan ZHENG College of Liberal Arts and Sciences National University of Defense TechnologyChangsha 410073China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

Combined shear-compression tests and simulations were performed on a closed-cell aluminum foam over a wide range of loading angles in order to probe their yield behaviors under biaxial loading *** shear-compression tests were carried out by using a pair of cylindrical bars with beveled *** yield surfaces were experimentally measured and compared with various theoretical yield surface *** cellular structures of closed-cell aluminum foams were modeled as tetrakaidecahedrons and their biaxial crushing behaviors were simulated by the finite element *** results show that,yield initiates from the stress-concentrated corners in the specimens under combined shear-compression loading and the stress distribution is no longer uniform at the specimen/bar *** the range of cell sizes studied,the larger the foam cell size is,the higher the yield stress *** foam density is found to be the dominant factor on its mechanical properties compared with the cell size and is much more significant in engineering practice.

关键词： combined shear-compression closed-cell aluminum foam yield surface biaxial loading yield behavior

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多层砌体房屋纵墙刚度不容忽视

山西科技 1996年第1期 48-48页

作者：刘维飞北京铁路局太原勘测设计院

多层砌体房屋纵墙刚度不容忽视刘维飞在工程设计中，习惯上将房屋短轴方向布置的墒称为横墙，长轴方向布置的墙称为纵墙。砌体房屋多数情况下横墙的刚度远小于纵墙的刚度。在确定砌体房屋静力计算方案时，只要横墙的刚度能满足刚性或刚... 详细信息

多层砌体房屋纵墙刚度不容忽视刘维飞在工程设计中，习惯上将房屋短轴方向布置的墒称为横墙，长轴方向布置的墙称为纵墙。砌体房屋多数情况下横墙的刚度远小于纵墙的刚度。在确定砌体房屋静力计算方案时，只要横墙的刚度能满足刚性或刚弹性方案房屋的刚度要求，即可确定整...

关键词： soil constitutive law plastic deformation yield surface flow rule.

Mathematical Model Analysis of Quasi Preconsolidation Soft Clay

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Journal of Southeast University(English Edition) 1998年第1期14卷 93-97页

作者：杨树才邓学钧韩世莲周虎鑫东南大学交通学院北京空军工程设计研究局

Soft clay may cause quasi preconsolidation effect under the constant hydrostatic pressure after some time. The result of drained triaxial test represents the effective stress yield surface, which can be described by simple binary linear fabric model. Therefore the pore pressure and deformation of clay can be decided. It also can be used to resolve the real boundary problems with finite element method.

关键词： soft clay quasi preconsolidation pressure yield surface deformation