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期刊论文 12

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2019 3

2018 3

2015 2

2013 1

2009 1

2007 2

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代表性体积元 1

多尺度均质化 1

晶格离散粒子模型 1

碱硅反应 1

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Stochastic analysis of laminated composite plate considering stochastic homogenization problem

S. SAKATA,K. OKUDA,K. IKEDA

《结构与土木工程前沿(英文)》 2015年 第9卷 第2期   页码 141-153 doi: 10.1007/s11709-014-0286-2

摘要: This paper discusses a multiscale stochastic analysis of a laminated composite plate consisting of unidirectional fiber reinforced composite laminae. In particular, influence of a microscopic random variation of the elastic properties of component materials on mechanical properties of the laminated plate is investigated. Laminated composites are widely used in civil engineering, and therefore multiscale stochastic analysis of laminated composites should be performed for reliability evaluation of a composite civil structure. This study deals with the stochastic response of a laminated composite plate against the microscopic random variation in addition to a random variation of fiber orientation in each lamina, and stochastic properties of the mechanical responses of the laminated plate is investigated. Halpin-Tsai formula and the homogenization theory-based finite element analysis are employed for estimation of effective elastic properties of lamina, and the classical laminate theory is employed for analysis of a laminated plate. The Monte-Carlo simulation and the first-order second moment method with sensitivity analysis are employed for the stochastic analysis. From the numerical results, importance of the multiscale stochastic analysis for reliability evaluation of a laminated composite structure and applicability of the sensitivity-based approach are discussed.

关键词: stochastic homogenization     multiscale stochastic analysis     microscopic random variation     laminated composite plate    

Three-scale stochastic homogenization of elastic recycled aggregate concrete based on nano-indentation

Chen WANG, Yuching WU, Jianzhuang XIAO

《结构与土木工程前沿(英文)》 2018年 第12卷 第4期   页码 461-473 doi: 10.1007/s11709-017-0441-7

摘要: In this paper, three-scale stochastic elastic finite element analyses are made for recycled aggregate concrete (RAC) based on nano-indentation digital images. The elastic property of RAC contains uncertainties across scales. It has both theoretical and practical values to model and predict its mechanical performance. Based on homogenization theory, effective stochastic elastic moduli of RAC at three different scales are obtained using moving window technique, nano-indentation digital images, and Monte-Carlo method. It involves the generation of a large number of random realizations of microstructure geometry based on different volume fraction of the inclusions and other parameters. The mean value, coefficient of variation and probability distribution of the effective elastic moduli are computed considering the material multiscale structure. The microscopic randomness is taken into account, and correlations of RAC among five phases are investigated. The effective elastic properties are used to obtain the global behavior of a composite structure. It is indicated that the response variability can be considerably affected by replacement percentage of recycled aggregates.

关键词: RAC     nano-indentation digital image     multiscale     microscopic randomness     homogenization    

Static analysis of corrugated panels using homogenization models and a cell-based smoothed mindlin plate

Nhan NGUYEN-MINH, Nha TRAN-VAN, Thang BUI-XUAN, Trung NGUYEN-THOI

《结构与土木工程前沿(英文)》 2019年 第13卷 第2期   页码 251-272 doi: 10.1007/s11709-017-0456-0

摘要: Homogenization is a promising approach to capture the behavior of complex structures like corrugated panels. It enables us to replace high-cost shell models with stiffness-equivalent orthotropic plate alternatives. Many homogenization models for corrugated panels of different shapes have been proposed. However, there is a lack of investigations for verifying their accuracy and reliability. In addition, in the recent trend of development of smoothed finite element methods, the cell-based smoothed three-node Mindlin plate element (CS-MIN3) based on the first-order shear deformation theory (FSDT) has been proposed and successfully applied to many analyses of plate and shell structures. Thus, this paper further extends the CS-MIN3 by integrating itself with homogenization models to give homogenization methods. In these methods, the equivalent extensional, bending, and transverse shear stiffness components which constitute the equivalent orthotropic plate models are represented in explicit analytical expressions. Using the results of ANSYS and ABAQUS shell simulations as references, some numerical examples are conducted to verify the accuracy and reliability of the homogenization methods for static analyses of trapezoidally and sinusoidally corrugated panels.

关键词: homogenization     corrugated panel     asymptotic analysis     smoothed finite element method (S-FEM)     cell-based smoothed three-node Mindlin plate element (CS-MIN3)    

混凝土中碱硅反应效应的多尺度均质化分析 Article

Roozbeh Rezakhani, Mohammed Alnaggar, Gianluca Cusatis

《工程(英文)》 2019年 第5卷 第6期   页码 1139-1154 doi: 10.1016/j.eng.2019.02.007

摘要:

碱硅反应(ASR)是混凝土结构(如桥梁和水坝)在长期的高湿度环境下发生的主要劣化机制之一。ASR是骨料中活性硅成分与水泥浆中碱金属离子之间发生的一种化学反应。这种化学反应会产生ASR凝胶,该凝胶吸水后膨胀,造成混凝土损坏和开裂,最终导致混凝土力学性能下降。本研究基于晶格离散粒子模型(LDPM),研究了混凝土的ASR损伤。LDPM可在粗骨料尺度上模拟混凝土,它是一种中尺度力学模型。作者已经成功地利用LDPM框架对ASR建模,并且通过实验数据对所得模型ASR-LDPM进行了校准和验证。本研究将ASR-LDPM用作中尺度模型,并采用最新开发的多尺度均质化框架来模拟ASR的宏观尺度效应。作者首先分析了由ASR-LDPM模拟的混凝土代表性体积元(RVE)在拉伸和压缩两种情况下的均质化行为,并研究了ASR对混凝土有效力学性能的影响。接下来,作者利用已开发的均质化框架再现了关于混凝土棱柱体自由体积膨胀的实验数据。最后,作者通过中尺度模型和所提出的多尺度方法,评估了压缩和四点弯曲梁中棱柱体的强度退化现象,以分析后者的准确性和计算效率。在所有数值分析中,作者考虑了具有不同内部粒子划分的RVE大小,以探讨它们对均质化响应的影响。

关键词: 多尺度均质化     代表性体积元     碱硅反应     晶格离散粒子模型    

New model of load transfer function for pile analysis based on disturbed state model

LIU Qijian, YANG Linde, WU Jun

《结构与土木工程前沿(英文)》 2007年 第1卷 第4期   页码 443-447 doi: 10.1007/s11709-007-0060-9

摘要: Based on the disturbed state concept (DSC), a new model of load transfer function for pile analysis is established by the idea that the deformed material between pile and soil can be treated as a mixture of two constituent parts, which are in intact or critical state and assumed to obey random distribution. Starting from the homogenization theory of heterogeneous materials and statistics method, a parameter to describe the disturbance degree is proposed, and a formula to determine the parameter has been derived by using the plastic displacement of a pile as distribution variable. In the model, shear intensity of elements in an intact state are simulated by Duncan-Zhang model and that in a critical state by Mohr-Coulomb criterion. The model of this paper has few parameters, which can reflect the aspects of load transfer function, such as hardening, softening and the effects of confining pressure. The well agreement between the in-situ data and the predicted shows that the validity of the model herein. So the proposed model in this paper is easy to be used in engineering practice.

关键词: hardening     homogenization     displacement     engineering     Duncan-Zhang    

Numerical modeling of nonlinear deformation of polymer composites based on hyperelastic constitutive law

Qingsheng YANG, Fang XU

《机械工程前沿(英文)》 2009年 第4卷 第3期   页码 284-288 doi: 10.1007/s11465-009-0067-0

摘要: Fiber reinforced polymer (FRP) composites exhibit nonlinear and hyperelastic characteristics under finite deformation. This paper investigates the macroscopic hyperelastic behavior of fiber reinforced polymer composites using a micromechanical model and finite deformation theory based on the hyperelastic constitutive law. The local stress and deformation of a representative volume element are calculated by the nonlinear finite element method. Then, an averaging procedure is used to find the homogenized stress and strain, and the macroscopic stress-strain curves are obtained. Numerical examples are given to demonstrate hyperelastic behavior and deformation of the composites, and the effects of the distribution pattern of fibers are also investigated to model the mechanical behavior of FRP composites.

关键词: composites     hyperelastic     finite deformation     homogenization     micromechanics    

Connected morphable components-based multiscale topology optimization

Jiadong DENG, Claus B. W. PEDERSEN, Wei CHEN

《机械工程前沿(英文)》 2019年 第14卷 第2期   页码 129-140 doi: 10.1007/s11465-019-0532-3

摘要: The advances of manufacturing techniques, such as additive manufacturing, have provided unprecedented opportunities for producing multiscale structures with intricate latticed/cellular material microstructures to meet the increasing demands for parts with customized functionalities. However, there are still difficulties for the state-of-the-art multiscale topology optimization (TO) methods to achieve manufacturable multiscale designs with cellular materials, partially due to the disconnectivity issue when tiling material microstructures. This paper attempts to address the disconnectivity issue by extending component-based TO methodology to multiscale structural design. An effective linkage scheme to guarantee smooth transitions between neighboring material microstructures (unit cells) is devised and investigated. Associated with the advantages of components-based TO, the number of design variables is greatly reduced in multiscale TO design. Homogenization is employed to calculate the effective material properties of the porous materials and to correlate the macro/structural scale with the micro/material scale. Sensitivities of the objective function with respect to the geometrical parameters of each component in each material microstructure have been derived using the adjoint method. Numerical examples demonstrate that multiscale structures with well-connected material microstructures or graded/layered material microstructures are realized.

关键词: multiscale topology optimization     morphable component     material microstructure     homogenization    

Two-scale modeling of granular materials: A FEM-FEM approach

Yun-Zhu CAI, Yu-Ching WU

《结构与土木工程前沿(英文)》 2013年 第7卷 第3期   页码 304-315 doi: 10.1007/s11709-013-0213-y

摘要: In the present paper, a homogenization-based two-scale FEM-FEM model is developed to simulate compactions of visco-plastic granular assemblies. The granular structure consisting of two-dimensional grains is modeled by the microscopic finite element method at the small-scale level, and the homogenized viscous assembly is analyzed by the macroscopic finite element method at large-scale level. The link between scales is made using a computational homogenization method. The two-scale FEM-FEM model is developed in which each particle is treated individually with the appropriate constitutive relations obtained from a representative volume element, kinematic conditions, contact constraints, and elimination of overlap satisfied for every particle. The method could be used in a variety of problems that can be represented using granular media.

关键词: homogenization     two-scale     representative volume element     compaction     granular assembly     finite element method    

Digital representation of meso-geomaterial spatial distribution and associated numerical analysis of geomechanics: methods, applications and developments

YUE Zhongqi

《结构与土木工程前沿(英文)》 2007年 第1卷 第1期   页码 80-93 doi: 10.1007/s11709-007-0008-0

摘要: This paper presents the author's efforts in the past decade for the establishment of a practical approach of digital representation of the geomaterial distribution of different minerals, particulars, and components in the meso-scale range (0.1 to 500 mm). The primary goal of the approach is to provide a possible solution to solve the two intrinsic problems associated with the current main-stream methods for geomechanics. The problems are (1) the constitutive models and parameters of soils and rocks cannot be given accurately in geomechanical prediction; and (2) there are numerous constitutive models of soils and rocks in the literature. The problems are possibly caused by the homogenization or averaging method in analyzing laboratory test results for establishing the constitutive models and parameters. The averaging method employs an assumption that the test samples can be represented by a homogeneous medium. Such averaging method ignores the fact that the geomaterial samples are also consisted of a number of materials and components whose properties may have significant differences. In the proposed approach, digital image processing methods are used as measurement tools to construct a digital representation for the actual spatial distribution of the different materials and components in geomaterial samples. The digital data are further processed to automatically generate meshes or grids for numerical analysis. These meshes or grids can be easily incorporated into existing numerical software packages for further mechanical analysis and failure prediction of the geomaterials under external loading. The paper presents case studies to illustrate the proposed approach. Further discussions are also made on how to use the proposed approach to develop the geomechanics by taking into account the geomaterial behavior at micro-scale, meso-scale and macro-scale levels. A literature review of the related developments is given by examining the SCI papers in the database of Science Citation Index Expanded. The results of this review have shown that the proposed approach is one of the latest research and developments in geomechanics where actual spatial distribution and properties of materials and components at the meso-level are taken into account.

关键词: homogeneous     numerical analysis     Expanded     homogenization     meso-level    

Computational model generation and RVE design of self-healing concrete

Md. Shahriar QUAYUM,Xiaoying ZHUANG,Timon RABCZUK

《结构与土木工程前沿(英文)》 2015年 第9卷 第4期   页码 383-396 doi: 10.1007/s11709-015-0320-z

摘要: Computational homogenization is a versatile tool that can extract effective properties of heterogeneous or composite material through averaging technique. Self-healing concrete (SHC) is a heterogeneous material which has different constituents as cement matrix, sand and healing agent carrying capsules. Computational homogenization tool is applied in this paper to evaluate the effective properties of self-healing concrete. With this technique, macro and micro scales are bridged together which forms the basis for multi-scale modeling. Representative volume element (RVE) is a small (microscopic) cell which contains all the microphases of the microstructure. This paper presents a technique for RVE design of SHC and shows the influence of volume fractions of different constituents, RVE size and mesh uniformity on the homogenization results.

关键词: homogenization     self-healing concrete (SHC)     representative volume element     multiscale modelling    

Macro-architectured cellular materials: Properties, characteristic modes, and prediction methods

Zheng-Dong MA

《机械工程前沿(英文)》 2018年 第13卷 第3期   页码 442-459 doi: 10.1007/s11465-018-0488-8

摘要:

Macro-architectured cellular (MAC) material is defined as a class of engineered materials having configurable cells of relatively large (i.e., visible) size that can be architecturally designed to achieve various desired material properties. Two types of novel MAC materials, negative Poisson’s ratio material and biomimetic tendon reinforced material, were introduced in this study. To estimate the effective material properties for structural analyses and to optimally design such materials, a set of suitable homogenization methods was developed that provided an effective means for the multiscale modeling of MAC materials. First, a strain-based homogenization method was developed using an approach that separated the strain field into a homogenized strain field and a strain variation field in the local cellular domain superposed on the homogenized strain field. The principle of virtual displacements for the relationship between the strain variation field and the homogenized strain field was then used to condense the strain variation field onto the homogenized strain field. The new method was then extended to a stress-based homogenization process based on the principle of virtual forces and further applied to address the discrete systems represented by the beam or frame structures of the aforementioned MAC materials. The characteristic modes and the stress recovery process used to predict the stress distribution inside the cellular domain and thus determine the material strengths and failures at the local level are also discussed.

关键词: architectured material     cellular materials     multi-scale modeling     homogenization method     effective material properties     computational method    

The effect of micro-structural uncertainties of recycled aggregate concrete on its global stochastic properties via finite pixel-element Monte Carlo simulation

Qingpeng MENG, Yuching WU, Jianzhuang XIAO

《结构与土木工程前沿(英文)》 2018年 第12卷 第4期   页码 474-489 doi: 10.1007/s11709-017-0442-6

摘要: In this paper, the effect of micro-structural uncertainties of recycled aggregate concrete (RAC) on its global stochastic elastic properties is investigated via finite pixel-element Monte Carlo simulation. Representative RAC models are randomly generated with various distribution of aggregates. Based on homogenization theory, effects of recycled aggregate replacement rate, aggregate volume fraction, the unevenness of old mortar, proportion of old mortar, aggregate size and elastic modulus of aggregates on overall variability of equivalent elastic properties are investigated. Results are in a good agreement with experimental data in literature and finite pixel-element method saves the computation cost. It is indicated that the effect of mesoscopic randomness on global variability of elastic properties is considerable.

关键词: RAC     Monte Carlo analysis     stochastic     finite pixel-element method     homogenization     coefficient of variation    

标题 作者 时间 类型 操作

Stochastic analysis of laminated composite plate considering stochastic homogenization problem

S. SAKATA,K. OKUDA,K. IKEDA

期刊论文

Three-scale stochastic homogenization of elastic recycled aggregate concrete based on nano-indentation

Chen WANG, Yuching WU, Jianzhuang XIAO

期刊论文

Static analysis of corrugated panels using homogenization models and a cell-based smoothed mindlin plate

Nhan NGUYEN-MINH, Nha TRAN-VAN, Thang BUI-XUAN, Trung NGUYEN-THOI

期刊论文

混凝土中碱硅反应效应的多尺度均质化分析

Roozbeh Rezakhani, Mohammed Alnaggar, Gianluca Cusatis

期刊论文

New model of load transfer function for pile analysis based on disturbed state model

LIU Qijian, YANG Linde, WU Jun

期刊论文

Numerical modeling of nonlinear deformation of polymer composites based on hyperelastic constitutive law

Qingsheng YANG, Fang XU

期刊论文

Connected morphable components-based multiscale topology optimization

Jiadong DENG, Claus B. W. PEDERSEN, Wei CHEN

期刊论文

Two-scale modeling of granular materials: A FEM-FEM approach

Yun-Zhu CAI, Yu-Ching WU

期刊论文

Digital representation of meso-geomaterial spatial distribution and associated numerical analysis of geomechanics: methods, applications and developments

YUE Zhongqi

期刊论文

Computational model generation and RVE design of self-healing concrete

Md. Shahriar QUAYUM,Xiaoying ZHUANG,Timon RABCZUK

期刊论文

Macro-architectured cellular materials: Properties, characteristic modes, and prediction methods

Zheng-Dong MA

期刊论文

The effect of micro-structural uncertainties of recycled aggregate concrete on its global stochastic properties via finite pixel-element Monte Carlo simulation

Qingpeng MENG, Yuching WU, Jianzhuang XIAO

期刊论文