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.

Viscosity Models Based on Network Theory for Polymer Melts

2010 ◽  
Vol 129-131 ◽  
pp. 1244-1247
Author(s):  
Hai Hang Xu ◽  
Lei Zhong
Keyword(s):  
Experimental Data ◽  
Kinetic Equation ◽  
Constitutive Equation ◽  
Polymer Composites ◽  
Network Theory ◽  
Polymer Melts ◽  
Structure Parameter ◽  
Viscosity Models ◽  
Model Predictions ◽  
Good Agreement

New shear and extensional viscosity models based on Fredrickson kinetic equation coupled with Dewitt constitutive equation were established to predict viscosities of polymer melts. The experimental data of 125°C LDPE and LDPE filled with 35% glass beads reported from references were compared with the model predictions. The predictions showed good agreement with the measurements. The models are simple and easy to use. Because they contain no structure parameter, they are capable to describe the viscosities of pure polymer and polymer composites.

scholarly journals Energy Dependence of Total Cross Sections for Reactions with 4, 6he, 6, 7, 9li Nuclei

KnE Energy ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 21
Author(s):  
Yu Penionzhkevich ◽  
Yu Sobolev ◽  
V Samarin ◽  
M Naumenko
Keyword(s):  
Experimental Data ◽  
Energy Range ◽  
Numerical Solution ◽  
Energy Dependence ◽  
Cross Sections ◽  
Beam Energy ◽  
Microscopic Analysis ◽  
Time Dependent ◽  
Total Cross Sections ◽  
Good Agreement

The paper presents the results of measurement of the total cross sections for reactions 4,6He + Si and 6,7,9Li + Si in the beam energy range 5−50 A⋅MeV. The enhancements of the total cross sections for reaction 6He + Si compared with reaction 4He + Si, and 9Li + Si compared with reactions 6,7Li + Si have been observed. The performed microscopic analysis of total cross sections for reactions 6He + Si and 9Li + Si based on numerical solution of the time-dependent Schrödinger equation for external neutrons of projectile nuclei 6He and 9Li yielded good agreement with experimental data.

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.

Prediction of Solid-Liquid Interface Stability and Dendritic Growth in Multi-Component Alloys with Calphad Method

2005 ◽  
Vol 475-479 ◽  
pp. 2721-2724
Author(s):  
Rui Jie Zhang ◽  
Zhi He ◽  
Wan Qi Jie
Keyword(s):  
Experimental Data ◽  
Present Method ◽  
Dendritic Growth ◽  
Calphad Method ◽  
Liquid Interface ◽  
Interface Stability ◽  
Calculation Results ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Good Agreement

A method to predict the solid-liquid interface stability and the constrained dendrite growth of multi-component alloys was developed based on the Calphad method. The method was applied to several industrial Al-Si-Mg alloys, and the predicted results were compared with some former experimental data. The good agreement between the calculation results and the experimental data demonstrates the superiority of the present method to the classical one based on constant parameter assumptions.

MODELING OF GOLD DISPERSION IN GLASSY POLYMERS BY SMOLUCHOWSKI EQUATION

2002 ◽  
Vol 13 (09) ◽  
pp. 1301-1312 ◽  
Author(s):  
ZBIGNIEW J. GRZYWNA ◽  
JACEK STOLARCZYK
Keyword(s):  
Differential Equation ◽  
Experimental Data ◽  
Partial Differential Equation ◽  
Smoluchowski Equation ◽  
Glassy Polymers ◽  
Time Dependent ◽  
Acetone Vapor ◽  
Induced Stress ◽  
Theoretical Predictions ◽  
Good Agreement

A unidimensional diffusion in a potential field of induced stress is considered. The way from random walk (RW) to limiting partial differential equation (Smoluchowski equation) for standard and time dependent RW is shown. A technologically important case of gold dispersion in crystallizing polymer swollen by acetone vapor is analyzed. Theoretical predictions based on Smoluchowski equation with time dependent coefficients are found to be in very good agreement with experimental data.

Aerodynamic Simulation of Vertical-Axis Wind Turbines

2013 ◽  
Vol 81 (2) ◽  
Author(s):  
A. Korobenko ◽  
M.-C. Hsu ◽  
I. Akkerman ◽  
Y. Bazilevs
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Vertical Axis ◽  
Time Dependent ◽  
Computational Results ◽  
Vertical Axis Wind Turbine ◽  
Vertical Axis Wind Turbines ◽  
Moving Domain ◽  
Aerodynamic Simulation ◽  
Good Agreement

Full-scale, 3D, time-dependent aerodynamics modeling and simulation of a Darrieus-type vertical-axis wind turbine (VAWT) is presented. The simulations are performed using a moving-domain finite-element-based ALE-VMS technique augmented with a sliding-interface formulation to handle the rotor-stator interactions present. We simulate a single VAWT using a sequence of meshes with increased resolution to assess the computational requirements for this class of problems. The computational results are in good agreement with experimental data. We also perform a computation of two side-by-side counterrotating VAWTs to illustrate how the ALE-VMS technique may be used for the simulation of multiple turbines placed in arrays.

Development and Validation of Multiscale Thermo-Elasto-Viscoplastic Analysis Method for Plain-Woven Composites

2019 ◽  
Vol 794 ◽  
pp. 78-88
Author(s):  
Gai Kubo ◽  
Tetsuya Matsuda ◽  
Hiroma Nagaoka ◽  
Yoshihiko Sato
Keyword(s):  
Present Method ◽  
Thermomechanical Properties ◽  
Homogenization Method ◽  
Woven Composites ◽  
Fiber Bundles ◽  
Analysis Method ◽  
Glass Fiber Reinforced Plastic ◽  
Glass Fiber Reinforced ◽  
Macro Scale ◽  
Woven Glass Fiber

In this study, the analysis method for thermomechanical properties of plain-woven composites is developed, and applied to thermoelastoviscoplastic analysis of plain-woven glass fiber-reinforced plastic (GFRP) composites. For this, a time-dependent constitutive equation depending on temperature for matrix materials is incorporated into the micro/meso/macro-scale thermo-elastic homogenization method for plain-woven composites developed by our research group. This method enables us to analyze thermoelastoviscoplastic properties in not only fiber bundles but also fibers and matrix materials in fiber bundles, as well as macroscopic thermal properties. This method is then applied to the thermal expansion analysis of a plain-woven GFRP composite subjected to a macroscopic temperature change from 25°C to 80°C before it is cooled to 25°C. Comparing the analysis results with experimental data, we validate the present method. It is also shown that the present method can evaluate themal residual stress and strain in the composite.

Application of the Surge Model to Radial Compressor System Cycle Optimization

2013 ◽  
Author(s):  
Viktor Kilchyk ◽  
Ahmed Abdelwahab ◽  
Andrew Rosinski
Keyword(s):  
Experimental Data ◽  
Open Loop ◽  
Time Dependent ◽  
Design Parameters ◽  
Radial Compressor ◽  
Lumped Parameter ◽  
Compressor Design ◽  
Compressor Efficiency ◽  
Good Agreement ◽  
Variable Coupling

Surge avoidance and minimization of power consumption in the design of a radial compressor cycle requires a solution to the complex, time-dependent problem of implicit variable coupling. To solve this problem, a modified lumped parameter surge model was developed and tested using experimental data. The model was expanded to include open-loop, time-dependent (periodic) boundary conditions with added equations representing the effects of heat transfer and flow compressibility. Comparison with experimental data showed good agreement with model-predicted behavior. The developed model of the compressor system was analyzed with respect to the main compressor design parameters. Sensitivity of the compressor system to the valve timing and resistance, wheel diameter, and inertia was also examined. It was demonstrated that the mass flow rate-averaged, or power-averaged compressor efficiency was improved by over 3 percent using the optimum impeller diameter.

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.

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