Towards Quantitatively Correct Micromechanics Models

1998 ◽  
pp. 405-417
Author(s):  
J. G. M. Mier ◽  
A. Vervuurt
Keyword(s):  
Micromechanics Models

scholarly journals Frequency-Dependent Tensile and Compressive Effective Moduli of Elastic Solids With Randomly Distributed Two-Dimensional Microcracks

2015 ◽  
Vol 82 (8) ◽  
Author(s):  
Youxuan Zhao ◽  
Yanjun Qiu ◽  
Laurence J. Jacobs ◽  
Jianmin Qu
Keyword(s):  
Wave Attenuation ◽  
Two Dimensional ◽  
Effective Moduli ◽  
The Finite Element Method ◽  
Elastic Solids ◽  
Frequency Dependent ◽  
Micromechanics Models ◽  
Dynamic Case ◽  
Crack Faces ◽  
Analytical Expressions

This paper develops micromechanics models to estimate the tensile and compressive elastic moduli of elastic solids containing randomly distributed two-dimensional microcracks. The crack faces are open under tension and closed under compression. When the crack faces are closed, they may slide against one another following the Coulomb's law of dry friction. The micromechanics models provide analytical expressions of the tensile and compressive moduli for both static and dynamic cases. It is found that the tensile and compressive moduli are different. Further, under dynamic loading, the compressive and tensile moduli are both frequency dependent. As a by-product, the micromechanics models also predict wave attenuation in the dynamic case. Numerical simulations using the finite element method (FEM) are conducted to validate the micromechanics models.

scholarly journals Micromechanical Modeling of Flexural Strength for Epoxy Polymer Concrete

2017 ◽  
Vol 09 (08) ◽  
pp. 1750117 ◽  
Author(s):  
Dongpeng Ma ◽  
Yiping Liu ◽  
Nanli Zhang ◽  
Zhenyu Jiang ◽  
Liqun Tang ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Epoxy Resin ◽  
Epoxy Polymer ◽  
Resin Content ◽  
Micromechanical Modeling ◽  
Polymer Concrete ◽  
Flexural Performance ◽  
Micromechanics Models ◽  
Strong Adhesion ◽  
Good Agreement

Epoxy polymer concrete (EPC) has been widely used in civil engineering nowadays due to its excellent mechanical properties and advantages in processing. In this paper, a modeling study has been carried out on the flexural performance of EPC. Two classic micromechanics models, i.e. rule of mixture and Mori-Tanaka method, are introduced to predict the flexural strength of EPC with various epoxy resin contents. The comparison shows that the parallel model based on the rule of mixture attains a good agreement with the measured results when the epoxy resin content is sufficiently high to achieve strong adhesion between the aggregate and the epoxy resin. In contrast, the Mori–Tanaka method with the failure criterion dominated by the weakest phase fails to give acceptable prediction due to the unsuitability of its basic assumptions to EPC, particularly when the epoxy resin content is at relatively high levels.

Stochastic Modeling of a High Speed Composite Flywheel for Energy Storage

2018 ◽  
Author(s):  
Matthew E. Riley ◽  
Justin Pettingill
Keyword(s):  
Magnetic Field ◽  
Stochastic Models ◽  
High Speed ◽  
Experimental Validation ◽  
Electromagnetic Response ◽  
Finite Element Models ◽  
Composite Flywheel ◽  
Optimal Geometry ◽  
Micromechanics Models ◽  
Supporting Materials

This work will demonstrate the development and experimental validation of the stochastic models to predict the composite material’s mechanical and electromagnetic response as a function of the constituent reinforcing materials. First, stochastic micromechanics models will be developed for the case of multiple disparate supporting materials. These micromechanics models will then be validated against traditional finite element models and experimental results over the feasible parameter space. The developed models will then be utilized to define the optimal geometry of the composite flywheel including constraints such as displacement, stress, flux, magnetic field density, and manufacturability.

A New Micromechanics Model for Predicting Thermal Properties of Heterogeneous Materials

2006 ◽  
Author(s):  
Wenbin Yu ◽  
Tian Tang
Keyword(s):  
Thermal Properties ◽  
Heterogeneous Materials ◽  
Present Theory ◽  
Unit Cell ◽  
Micromechanics Model ◽  
Micromechanics Models ◽  
Unit Cells ◽  
Variational Asymptotic ◽  
Variational Asymptotic Method ◽  
Complete Set

A new micromechanics model, namely, the variational asymptotic method for unit cell homogenization (VAMUCH), is extended to predict thermal properties of heterogeneous anisotropic materials. In comparison to existing micromechanics models, VAMUCH is unique in the following three aspects: (1) it invokes only essential assumptions within the concept of micromechanics and achieves the same accuracy as mathematical homogenization theories; (2) it calculates the complete set of properties simultaneously without applying any loads; and (3) the dimensionality of the problem is determined by the dimension of the unit cell and the complete set of material properties can be obtained for one-dimensional unit cells. The present theory is implemented in the computer program VAMUCH, a recently developed, versatile engineering code for homogenization of heterogeneous materials. Several examples will be used to demonstrate the application and accuracy of the theory and the code of VAMUCH.

Simulation-based verification of homogenization approach in predicting effective thermal conductivities of wavy orthotropic fiber composite

2019 ◽  
Vol 08 (04) ◽  
pp. 1950015
Author(s):  
C. Mahesh ◽  
K. Govindarajulu ◽  
V. Balakrishna Murthy
Keyword(s):  
Volume Fraction ◽  
Fiber Composite ◽  
Micromechanical Model ◽  
Two Stage ◽  
Micromechanics Models ◽  
Simulation Based ◽  
Homogenization Approach ◽  
Homogenized Model ◽  
Good Agreement ◽  
Thermal Conductivities

In this work, applicability of homogenization approach is verified with the micromechanics approach by considering wavy orthotropic fiber composite. Thermal conductivities of [Formula: see text]-300 orthotropic wavy fiber composite are determined for micromechanical model and compared with the results obtained by two stage homogenized model over volume fraction ranging from 0.1 to 0.6. Also, a methodology is suggested for reducing percentage deviation between homogenization and micromechanical approaches. Effect of debond on the thermal conductivities of wavy orthotrophic fiber composite is studied and compared with perfectly aligned fiber composite for different volume fraction. It is observed that results obtained by the homogenization approach are in good agreement with the results obtained through micromechanics approach. Maximum percentage deviation between homogenized and micromechanics models is 2.13%.

The effect of micromechanics models on mechanical property predictions for short fiber composites

2020 ◽  
Vol 244 ◽  
pp. 112229 ◽  
Author(s):  
Jian Zhao ◽  
Dong-Xiao Su ◽  
Jin-ming Yi ◽  
Gengdong Cheng ◽  
Lih-Sheng Turng ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Fiber Composites ◽  
Short Fiber ◽  
Micromechanics Models

Fracture Analysis of Sinusoidal CNT-Based Nanocomposites with Uniform and Nonuniform CNT Distributions

NANO ◽  
2015 ◽  
Vol 10 (04) ◽  
pp. 1550058 ◽  
Author(s):  
Hossein Golestanian ◽  
Mahdieh Hamedi
Keyword(s):  
Finite Element ◽  
Carbon Nanotube ◽  
Failure Mechanisms ◽  
Fracture Analysis ◽  
Finite Element Simulations ◽  
Strain Diagram ◽  
Reinforced Polymers ◽  
Reinforced Polymer ◽  
Micromechanics Models ◽  
Simulation Results

In this investigation, the effects of carbon nanotube (CNT) shape and distribution on nanocomposite failure are investigated. To achieve our goals, nanocomposites consisting of straight and sinusoidal CNTs with uniform and nonuniform distributions have been modeled. Failure of these nanocomposites is investigated using finite element simulations and micromechanics models. Initially, straight CNT-reinforced polymer is simulated and the stress–strain diagram for this nanocomposite is obtained. To validate our models, the simulation results of this nanocomposite are compared with those found in the literature. Then, sinusoidal CNT-reinforced polymers with uniform and nonuniform CNT distributions are modeled. The results are compared to determine the influence of CNT shape and distribution on nanocomposite failure mechanisms.

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