Ceramic Fiber - Fluoropolymer Composites for Electronic Packaging Materials

1989 ◽  
Vol 155 ◽  
Author(s):  
John D. Bolt
Keyword(s):  
Fiber Composites ◽  
Short Fiber ◽  
Dielectric Constants ◽  
Woven Fabric ◽  
Ceramic Fiber ◽  
Fiber Volume ◽  
Woven Fabric Composites ◽  
Fabric Composites ◽  
Out Of Plane ◽  
Thermal Conductivities

ABSTRACTAluminum nitride (AIN), alumina and aramid fibers have been incorporated into epoxy and fluoropolymer matrices. The fluoropolymer composites have dielectric constants less than 3.4 and losses below 0.3%, measured out-of-plane. In-plane and out-of-plane thermal conductivities of the AIN-fluoropolymer composites averaged 5.2 and 1.3 W/mK, respectively, at fiber volume fractions of 0.26 to 0.29. In-plane thermal conductivities of woven fabric composites were accurately predicted by mixing rules; for non-woven and short fiber composites, thermal conductivities were less than predicted. These composites had higher out-of-plane thermal conductivities due to out-of-plane components of the fiber orientations.

Measurement and Prediction of Effective Thermal Conductivity for Woven Fabric Composites

2003 ◽  
Vol 17 (08n09) ◽  
pp. 1808-1813 ◽  
Author(s):  
Nam Seo Goo ◽  
Kyeongsik Woo
Keyword(s):  
Fiber Volume Fraction ◽  
Volume Fraction ◽  
Woven Fabric ◽  
Fiber Volume ◽  
Plain Weave ◽  
Woven Fabric Composites ◽  
Weave Fabric ◽  
Experimental Apparatus ◽  
Fabric Composites ◽  
Thermal Conductivities

The current paper deals with the measurement and prediction of thermal conductivities for plain weave fabric composites. An experimental apparatus was setup to measure the temperature gradients from which the thermal conductivities were obtained. The thermal conductivities were also calculated using finite element analyses for plain weave unit cell models and then compared with experimental results. In addition, the effect of a phase shift and the fiber volume fraction in the tow on the thermal conductivities was addressed.

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.

Thermal conductivities of three-dimensionally woven fabric composites

2008 ◽  
Vol 68 (9) ◽  
pp. 2085-2091 ◽  
Author(s):  
J SCHUSTER ◽  
D HEIDER ◽  
K SHARP ◽  
M GLOWANIA
Keyword(s):  
Woven Fabric ◽  
Woven Fabric Composites ◽  
Fabric Composites ◽  
Thermal Conductivities

Effect of warp and fill-fiber volume fractions on mechanical properties of glass/epoxy woven fabric composites

2020 ◽  
Vol 54 (24) ◽  
pp. 3501-3513
Author(s):  
Mohammad Aghaei ◽  
Mahmood M Shokrieh ◽  
Reza Mosalmani
Keyword(s):  
Mechanical Properties ◽  
Micromechanical Model ◽  
Woven Fabrics ◽  
Woven Fabric ◽  
Experimental Program ◽  
Fiber Volume ◽  
Volume Fractions ◽  
Woven Fabric Composites ◽  
New Concepts ◽  
Fabric Composites

Mechanical properties of woven fabric composites are influenced by fabric geometry and harness. In the present research, woven fabric composites made of ML-506 epoxy resin and E-glass woven fabrics with three different fabric geometries (harnesses of 2, 5, and 8) were studied experimentally. The new concepts of warp and fill-fiber volume fractions were introduced. Based on these new concepts, a micromechanical model for predicting the stiffness and strength of composites made of woven fabrics was developed. An experimental program was conducted to evaluate the present model and the new concepts of warp and fill-fiber volume fractions. The results obtained by the new micromechanical model have been compared with the conducted experimental results as well as the experimental data available in the literature, and very good correlations were obtained.

Measuring and modeling the thermal conductivities of three-dimensionally woven fabric composites

2009 ◽  
Vol 45 (2) ◽  
pp. 165-174 ◽  
Author(s):  
J. Schuster ◽  
D. Heider ◽  
K. Sharp ◽  
M. Glowania
Keyword(s):  
Woven Fabric ◽  
Woven Fabric Composites ◽  
Fabric Composites ◽  
Thermal Conductivities

Effect of Nesting of Fiber Bundles on Micro Fracture of Laminated Woven Fabric Composite

2002 ◽  
Author(s):  
Toshiko Osada ◽  
Asami Nakai ◽  
Hiroyuki Hamada
Keyword(s):  
Volume Fraction ◽  
Woven Fabric ◽  
Fiber Bundles ◽  
Fiber Volume ◽  
Woven Fabric Composites ◽  
Number Of Layers ◽  
Fabric Composite ◽  
Knee Point ◽  
Fabric Composites ◽  
Layer Increase

In laminated woven fabric composites, fiber bundles do not pack tightly because there are resin rich regions caused by crimp of fiber bundles. The fiber bundles in one layer are often fitted into the neighboring layer, which is called nesting. In this study, the effect of nesting by laminating on mechanical properties and micro fracture behavior of composites was investigated. Tensile testing of woven fabric composites with different number of layers and observation using optical microscopy were performed. With the increase of number of layers, nesting is more likely to occur, resulting in a decrease in thickness per layer increase in fiber volume fraction. This also lead to an increase in modulus and strength but a decrease in knee point stress. The locations at which cracks occurred were different in specimens with and without nesting.

Thermo-Mechanical Modeling of 3D Woven Fabric Composites Using Two-Step Homogenization Approach

2019 ◽  
Author(s):  
Nagappa Siddgonde ◽  
Anup Ghosh
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Woven Fabric ◽  
Fiber Volume ◽  
Woven Fabric Composites ◽  
Fabric Composite ◽  
Fabric Composites ◽  
Matrix Properties ◽  
Homogenization Approach ◽  
3D Fea

Abstract A 3D finite element based Representative Volume Element (RVE) model has been developed to predict the thermo-mechanical properties of 3D orthogonal interlock woven fabric composites (OIWFC) and angle interlock woven fabric composite (AIWFC) using a two-step homogenization approach. The first step homogenization, micro-homogenization, deals with resin infiltration effect of yarn as a unidirectional continuous fiber with an assumption of 80 percent of fiber volume fraction based on initial fiber and matrix properties. The second step, meso-homogenization, predicts effective thermo-mechanical properties of 3D woven fabric composites based on effective yarn and matrix properties. The RVE analysis has been performed using 3D FEA method with periodic boundary conditions (PBCs). Further, a void study has been performed considering the influences of void on thermo-mechanical properties of the 3D woven fabric composite. It is noted that the influence of void contents plays a significant role in predicting the thermo-mechanical properties of the 3D WFC. The thermo-mechanical properties gradually decrease with an increase of void contents. Studies have been carried out considering the same fiber volume fractions in both 3D WFC models. An AIWFC model predicts higher values of thermo-mechanical constants than OIWFC model.

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