Effects of Laminate Misalignment on Thermoelastoviscoplastic Properties of Ultrafine Plate-Fin Structures

2014 ◽  
Vol 626 ◽  
pp. 301-306
Author(s):  
Yuki Yamanaka ◽  
Tetsuya Matsuda
Keyword(s):  
Present Method ◽  
Unit Cell ◽  
Time Dependent ◽  
Homogenization Theory ◽  
Substructure Method ◽  
Temperature Increment

Effects of laminate misalignment on the thermoelastoviscoplastic properties of ultrafine plate-fin structures are investigated using a homogenization theory for thermoelastoviscoplasticity. For this, a homogenization theory for time-dependent materials is combined with a homogenization theory for thermoelasticity. Moreover, the substructure method is introduced into the theory to deal with the random laminate misalignment in ultrafine plate-fin structures. The present method is then applied to the analysis of thermoelastoviscoplastic behavior of ultrafine plate-fin structures made of a Ni-based alloy subjected to a macroscopic temperature increment from 20 to 200. The number of fin layers in a unit cell is five kinds, i.e. N = 10, 20, 30, 40 and 50, for each of which, twenty patterns of random laminate misalignment are considered. In addition, five cases of periodic laminate misalignment are also considered for comparison. The results reveal the effects of the laminate misalignment on the macroscopic and microscopic thermoelastoviscoplastic properties of ultrafine plate-fin structures.

Macro/Meso/Micro Elastic-Viscoplastic Analysis of Plain-Woven Laminates Using Homogenization Theory

2014 ◽  
Vol 626 ◽  
pp. 365-371 ◽  
Author(s):  
Kohei Oide ◽  
Tetsuya Matsuda
Keyword(s):  
Experimental Data ◽  
Constitutive Equation ◽  
Glass Fiber ◽  
Present Method ◽  
Time Dependent ◽  
Homogenization Theory ◽  
Fiber Bundles ◽  
Woven Glass Fiber ◽  
Good Agreement

In this study, macro/meso/micro elastic-viscoplastic analysis of plain-woven laminates is conducted based on a homogenization theory for nonlinear time-dependent composites. For this, a plain-woven laminate is modeled with respect to three scales by considering the laminate as a macrostructure, fiber bundles (yarns) and a matrix in the laminate as a mesostructure, and fibers and a matrix in the yarns as a microstructure. Then, an elastic-viscoplastic constitutive equation of the laminate is derived by dually applying the homogenization theory for nonlinear time-dependent composites to not only the meso/micro but also the macro/meso scales. Using the present method, the elastic-viscoplastic analysis of a plain-woven glass fiber/epoxy laminate subjected to on-and off-axis loading is performed. It is shown that the present method successfully takes into account the effects of viscoplasticity of the epoxy in yarns on the elastic-viscoplastic behavior of the plain-woven GFRP laminate. It is also shown that the results of analysis are in good agreement with experimental data.

MULTI-SCALE CREEP ANALYSIS OF PLAIN-WOVEN LAMINATES USING TIME-DEPENDENT HOMOGENIZATION THEORY: EFFECTS OF LAMINATE CONFIGURATION

2008 ◽  
Vol 22 (31n32) ◽  
pp. 6173-6178 ◽  
Author(s):  
K. NAKATA ◽  
T. MATSUDA ◽  
M. KAWAI
Keyword(s):  
Boundary Condition ◽  
Glass Fiber ◽  
Creep Behavior ◽  
Present Method ◽  
Time Dependent ◽  
Homogenization Theory ◽  
Multi Scale ◽  
Creep Analysis ◽  
Internal Structures ◽  
Woven Glass Fiber

In this study, multi-scale creep analysis of plain-woven GFRP laminates is performed using the time-dependent homogenization theory developed by the present authors. First, point-symmetry of internal structures of plain-woven laminates is utilized for a boundary condition of unit cell problems, reducing the domain of analysis to 1/4 and 1/8 for in-phase and out-of-phase laminate configurations, respectively. The time-dependent homogenization theory is then reconstructed for these domains of analysis. Using the present method, in-plane creep behavior of plain-woven glass fiber/epoxy laminates subjected to a constant stress is analyzed. The results are summarized as follows: (1) The in-plane creep behavior of the plain-woven GFRP laminates exhibits marked anisotropy. (2) The laminate configurations considerably affect the creep behavior of the laminates.

Elastic-Viscoplastic Behaviour of Plain-Woven GFRP Laminates: Analysis Using Homogenization Theory

2007 ◽  
Vol 334-335 ◽  
pp. 45-48
Author(s):  
Tetsuya Matsuda ◽  
Y. Nimiya ◽  
Nobutada Ohno ◽  
Masamichi Kawai
Keyword(s):  
Present Method ◽  
Room Temperature ◽  
Constant Strain Rate ◽  
Tensile Tests ◽  
Time Dependent ◽  
Homogenization Theory ◽  
Point Symmetry ◽  
Quantitative Prediction ◽  
Viscoplastic Deformation ◽  
Internal Structures

In the present study, a method for reducing the domain of analysis is developed for the homogenization analysis of plain-woven laminates. Moreover, the method is applied to the quantitative prediction of elastic-viscoplastic deformation of plain-woven GFRP laminates. It is first shown that the internal structures of plain-woven laminates satisfy point-symmetry on the assumption that the laminates have the in-phase or out-of-phase laminate configuration of plain fabrics. The point-symmetry is then utilized for the boundary condition of unit cell problems, reducing the domain of analysis to 1/4 and 1/8 for the in-phase and out-of-phase laminate configurations, respectively. Using the present method combined with the nonlinear time-dependent homogenization theory, the elastic-viscoplastic behavior of plain-woven GFRP laminates under in-plane on- and off-axis loading is analyzed. In addition, the tensile tests of a plain-woven GFRP laminate at a constant strain rate are performed at a room temperature. Comparing the results of the present analysis with the experimental ones, it is shown that the analysis successfully predicts the in-plane elastic-viscoplastic behavior of the plain-woven GFRP laminate.

scholarly journals Thermo-Viscoelastic Response of 3D Braided Composites Based on a Novel FsMsFE Method

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 271
Author(s):  
Jun-Jun Zhai ◽  
Xiang-Xia Kong ◽  
Lu-Chen Wang
Keyword(s):  
Finite Element ◽  
Cell Model ◽  
Structural Parameters ◽  
Thermal Relaxation ◽  
Viscoelastic Behavior ◽  
Unit Cell ◽  
Time Dependent ◽  
3D Braided Composites ◽  
Equivalent Time ◽  
Representative Unit Cell

A homogenization-based five-step multi-scale finite element (FsMsFE) simulation framework is developed to describe the time-temperature-dependent viscoelastic behavior of 3D braided four-directional composites. The current analysis was performed via three-scale finite element models, the fiber/matrix (microscopic) representative unit cell (RUC) model, the yarn/matrix (mesoscopic) representative unit cell model, and the macroscopic solid model with homogeneous property. Coupling the time-temperature equivalence principle, multi-phase finite element approach, Laplace transformation and Prony series fitting technology, the character of the stress relaxation behaviors at three scales subject to variation in temperature is investigated, and the equivalent time-dependent thermal expansion coefficients (TTEC), the equivalent time-dependent thermal relaxation modulus (TTRM) under micro-scale and meso-scale were predicted. Furthermore, the impacts of temperature, structural parameters and relaxation time on the time-dependent thermo-viscoelastic properties of 3D braided four-directional composites were studied.

scholarly journals Multiscale Evaluation of The Elastic Behavior for The Metal-Coated Lattice Structures

2020 ◽  
Author(s):  
Sina Soleimanian ◽  
Xiang Wang ◽  
Min Chen ◽  
Yanqing Yu ◽  
Ji Li ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Film Thickness ◽  
Volume Fraction ◽  
Effective Properties ◽  
Unit Cell ◽  
Homogenization Theory ◽  
Elastic Behavior ◽  
Coating Film ◽  
Specific Modulus ◽  
The Impact

Abstract Well-developed Additive Manufacturing leads to a variety of material and structure design. With the combination of 3D printing and plating technique, metal-coated resin lattice is investigated to achieve a light weight design with minimal economic cost and admirable material properties. In this paper, numerical approaches integrated with classical homogenization theory is adopted to study the effective mechanical characterizations of the BCC (Body-Centered-Cubic) metal-coated lattices. The selection of RVE (Representative Volume Element) is discussed for obtaining objective effective properties. Moreover, the impact of unit cell rod diameter and coating film thickness are investigated. A sensitivity analysis of these two parameters is conducted based on the advanced hypercube sampling methods. The results reveal that multiple-unit-cells lead to more stable homogenized properties than single unit cell. The Increase of volume fraction may improve the elastic modulus and specific modulus remarkably. However, the increase of thickness of coating film only leads to monotonously increased elastic modulus. For this reason, there exists an optimal coating film thickness for the specific modulus of the lattice structure.

Minimum Wall Distance Computations With Time-Dependent Geometry for CFD

2021 ◽  
Author(s):  
Liwu Wang ◽  
Jian Feng ◽  
Yu Liu ◽  
Sijun Zhang
Keyword(s):  
Present Method ◽  
Turbulence Models ◽  
Time Dependent ◽  
Navier Stokes ◽  
Field Function ◽  
Convection Diffusion ◽  
Convection Diffusion Equation ◽  
Wall Distance ◽  
Rans Turbulence Models ◽  
Computational Fluid Dynamics Cfd

Abstract This paper presents an efficient and scalable method to calculate the minimum wall distance (MWD), which is necessary for the Reynolds-Averaged Navier-Stokes (RANS) turbulence models. The MWD is described by the distance field function which is essentially a partial differential equation (PDE). The PDE is a type of convection-diffusion equation and can be solved by existing computational fluid dynamics (CFD) codes with minor modifications. Parallel computations for the PDE are conducted to study its efficiency and scalability. Encouraging results are obtained and demonstrate the present method is more efficient than all the alternate methods.

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