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Simulation on Thermal Physical Properties of Fine Weave Pierced C/C Composite

Author: ChenShengHong
Tutor: ChenGuiQing
School: Harbin Institute of Technology
Course: Materials Science
Keywords: FINE WEAVE puncture C / C composites Coefficient of thermal expansion Thermal diffusion performance Finite Element Simulation
CLC: TB332
Type: Master's thesis
Year: 2008
Downloads: 47
Quote: 0
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Abstract

The fine editing puncture fabrics has a good overall structure and higher fiber volume fraction, is an excellent substrate of the production of high-performance heat-resistant insulation in C / C composite. This paper studies the variation with temperature from room temperature to 1200 ℃ material thermal expansion properties and thermal diffusion performance, numerical simulation of cross-ply 0 ° / 90 ° and 0 ° / 90 ° / ± 45 ° laying material thermophysical properties, analysis thermal expansion properties and thermal diffusion performance influencing factors, the relationship between the material thermophysical properties and structure of materials. The main contents of this paper and the results are as follows: The experimental results show that the thermal expansion properties: from room temperature to 1200 ° C and 0 ° / 90 ° cross-ply and 0 ° / 90 ° / ± 45 ° laying materials xy to the coefficient of thermal expansion are higher than z direction, since the role of the holes and gaps in the material, the thermal expansion coefficient is dramatically reduced as the temperature rises first, and then as the temperature rises generally upward trend. 0 ° / 90 ° / ± 45 ° the structural integrity of the paving materials is strong, so the coefficient of thermal expansion of the material with increasing temperature and reduced, decreasing tendency is more intense, and then increases with increasing temperature, increasing relatively stable trend. Simulated cross-ply 0 ° / 90 ° and 0 ° / 90 ° / ± 45 ° laying material thermal expansion properties, simulation error within 20%, indicating that the model is reasonable. The matrix and the fibers relative content material the final thermal expansion coefficient, so the fiber bundles elliptical cross-sectional simulation obtained of z to and xy to the coefficient of thermal expansion than the corresponding square cross-sectional large; material with increasing volume fraction of fiber, Z material to reduce the coefficient of thermal expansion and the xy direction; the z-direction and xy to the coefficient of thermal expansion, with the laying of different ways, resulting in a regular variation. Experimental results show that the thermal diffusion properties: 0 ° / 90 ° cross-ply and the 0 ° / 90 ° / ± 45 ° paving materials XY to thermal diffusivity and thermal conductivity, thermal diffusivity and thermal conductivity greater than the z-direction rate declining as the temperature increases, which is caused by the microstructure of the material changes, the z-direction of the material and xy to the thermal diffusion coefficient with increasing temperature difference becomes smaller, the specific heat of the material with increasing temperature increases. 0 ° / 90 ° / ± 45 ° laying material structural integrity, and the thermal diffusivity of the material z-direction and the xy direction becomes gradually smaller with increasing temperature difference, the difference becomes smaller tendency than 0 ° / 90 ° orthogonal laying the obvious. Simulated cross-ply 0 ° / 90 ° and 0 ° / 90 ° / ± 45 ° laying thermal diffusion properties, simulate the boundary conditions of the simulation and experimental inconsistent error, error -20%. Fiber bundle elliptical cross-sectional shape corresponding to square cross section, the thermal diffusivity and specific heat is increased, resulting in thermal conductivity also increases; thermal diffusivity and specific heat is reduced with the increase of the volume fraction of fibers, the thermal conductivity decreases.

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CLC: > Industrial Technology > General industrial technology > Materials science and engineering > Composite materials > Non-metallic composite materials
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