A Multi-Scale Analysis for an Evaluation of the Mechanical Properties of Composite Materials

2007 ◽  
Vol 334-335 ◽  
pp. 585-588
Author(s):  
Makoto Imura ◽  
Tetsusei Kurashiki ◽  
Hiroaki Nakai ◽  
Masaru Zako
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Composite Materials ◽  
Material Properties ◽  
Woven Fabric ◽  
Scale Analysis ◽  
Multi Scale ◽  
Woven Fabric Composites ◽  
Fabric Composites ◽  
Multi Scale Analysis

Fiber reinforced composite materials have been applied widely to many structures, because they have some advantages like easy handling, high specific strength, etc. The numerical method like finite element method has been applied to design and to evaluate the material properties and behavior as the development of Computer Aided Engineering. It is very difficult to calculate with accuracy not only in structural scale but also in detail material scale (for example, the order of fiber diameter) by the traditional FEM, becausecompositematerials like woven fabric composites have the geometrical complexityand the large difference between above mentioned scales. The development of multi-scale analysis method is one of the major topics in computational mechanics. Mesh superpositionis one of multi-scale analysis methods and is an effective method to solve the problems which have the large difference between the structure scale and the reinforcement scale. We have expanded the finite element mesh superposition method with 3 scales and have defined as M3 (Macro-Meso-Micro) method. In this paper, we have proposed a new approach method combined with M3 method and homogenized method to obtain the mechanical properties and to simulate the behavior of woven fabric composites. In addition, the elastic-plastic mechanics and the damage mechanics have been introduced into M3 method to investigate the effects of matrix-crack on the structural and material properties. From the numerical results, it is revealed that it is very useful for the evaluation of mechanical properties of composite materials.

scholarly journals An MMF3 Criterion Based Multi-Scale Strategy for the Failure Analysis of Plain-Woven Fabric Composites and Its Validation in the Open-Hole Compression Tests

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4393
Author(s):  
Rui Zhou ◽  
Weicheng Gao ◽  
Wei Liu
Keyword(s):  
Woven Fabric ◽  
Scale Analysis ◽  
Micro Scale ◽  
Multi Scale ◽  
Woven Fabric Composites ◽  
Numerical Predictions ◽  
Fabric Composites ◽  
Open Hole ◽  
Meso Scale ◽  
Multi Scale Analysis

A modified micromechanics failure criterion (MMF3) based multi-scale analysis strategy was proposed in this article to analyze the failure behaviors of the plain-woven fabric composites. The finite-element (FE) representative unit cell (RUC) models of different scales were first established, and the RUC based stress transformation methods were developed. The micro-scale strengths of the constituents in the unidirectional laminate were achieved based on the tested macro-scale strengths. Under the micro-scale strength invariance hypothesis, the meso-scale strengths of the fiber tows from the plain-woven fabric composites were back-calculated first and were then validated and corrected with the assistance of tested strengths of the fabric laminates. With the micro-scale RUC and the calculated meso-scale strengths of the fiber tows, the micro-scale strengths of the constituents suitable for the plain-woven fabric composites were determined. The multi-scale analysis procedure for the plain-woven fabric composites was then established in providing a more direct failure observation at the constituent level. Open-hole compression specimens were tested according to the ASTM standard D6484, and the failure of the open-hole fabric laminate was simulated with the proposed multi-scale strategy. The numerical predictions were in good agreement with the experimental results, and the feasibility of the multi-scale strategy was validated.

A Proposal of Calculation Method for Equivalent Property of Composite Materials

2007 ◽  
Vol 334-335 ◽  
pp. 241-244
Author(s):  
Hiroaki Nakai ◽  
Hiromasa Tomioka ◽  
Tetsusei Kurashiki ◽  
Masaru Zako
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Calculation Method ◽  
Woven Fabric ◽  
Superposition Method ◽  
Woven Fabric Composites ◽  
Traditional Procedure ◽  
Fabric Composites ◽  
Equivalent Property ◽  
Good Agreement

To predict the mechanical properties of composite materials by using computer is complicated, because it is difficult to model directly by ordinary FEM. A calculation method by using the mesh superposition method and periodic boundary condition has been proposed in order to obtain the equivalent mechanical properties of composite materials easily. The numerical results by proposed method have shown good agreement with ones by the traditional procedure. The proposed method is efficient for the materials with complicated structure like woven fabric composites etc.

scholarly journals Structure optimization of woven fabric composites for improvement of mechanical properties using a micromechanics model of woven fabric composites and a genetic algorithm

2021 ◽  
Vol 30 ◽  
pp. 263498332110061
Author(s):  
Gunyong Hwang ◽  
Dong Hyun Kim ◽  
Myungsoo Kim
Keyword(s):  
Mechanical Properties ◽  
Genetic Algorithm ◽  
Elastic Modulus ◽  
Fiber Composite ◽  
Woven Fabric ◽  
Cross Sectional ◽  
Micromechanics Model ◽  
Woven Fabric Composites ◽  
Fabric Composites ◽  
Out Of Plane

This research aims to optimize the mechanical properties of woven fabric composites, especially the elastic modulus. A micromechanics model of woven fabric composites was used to obtain the mechanical properties of the fiber composite, and a genetic algorithm (GA) was employed for the optimization tool. The structure of the fabric fiber was expressed using the width, thickness, and wave pattern of the fiber strands in the woven fabric composites. In the GA, the chromosome string consisted of the thickness and width of the fill and warp strands, and the objective function was determined to maximize the elastic modulus of the composite. Numerical analysis showed that the longitudinal mechanical properties of the strands contributed significantly to the overall elastic modulus of the composites because the longitudinal property was notably larger than the transverse property. Therefore, to improve the in-plane elastic modulus, the resulting geometry of the composites possessed large volumes of related strands with large cross-sectional areas and small strand waviness. However, the numerical results of the out-of-plane elastic modulus generated large strand waviness, which contributed to the fiber alignment in the out-of-plane direction. The findings of this research are expected to be an excellent resource for the structural design of woven fabric composites.

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