Summary: | 碩士 === 逢甲大學 === 紡織工程所 === 91 === The fiber rigid model to calculate the thermal expansion coefficient of the woven fabric composites, and consider the thermal applied force of fiber and matrix. Further, the effects of various parameters on the thermal expansion properties of fabric composites will be investigated. This analysis method considers the arrange and crimp among all fiber tows in the unit cell, and joins thermal applied force in the model to obtain the thermal expansion coefficient of the woven fabric composites. Unit cell will be incised infinitesimal pieces, when analyzing thermal expansion coefficient of woven fabric composites. Then, suppose every piece thermal amount of deformation equivalency along the same direction. The thermal applied force of fiber and matrix were embedded analysis mode to calculate thermal expansion coefficient of every piece. At the latest, thermal expansion coefficient of all pieces are assembled in series along thickness direction. Hence, the result obtained thermal expansion coefficient amass expressions of unit cell. Furthermore, the calculated thermal expansion coefficient correlate the experimental results.
Primary, the effects of fiber volume fraction and the height / length (H/L) ration of the unit cell on the thermal expansion coefficients of plain woven composites were calculated. The results show that the thermal expansion coefficients decrease with increasing fiber volume fraction for a constant. H/L ration. On the other hand, for a constant H/L ration, the thermal expansion coefficients decrease with increasing fiber volume fraction. Furthermore, the relative shift of the neighboring laminate is observed to have very limited effect on the thermal expansion coefficient of the woven laminate. As for the comparison of the thermal expansion coefficient among those three different fabric composites, for a constant fiber volume fraction and fiber tow wavetable. Conclusion, the thermal expansion coefficient is which plain fabric composite has the highest value and the satin fabric composite yield the lowest for a constant crimp of the fiber tows.
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