| Summary: | 碩士 === 逢甲大學 === 紡織工程學系 === 88 === In this study, carbon fiber plain woven fabrics were laminated to produce C-beam perform with various cross-sections. The Resin Transfer Molding technique was used to transfer resin into the mold by pressure difference. After the appropriate curing processes, the laminated plain woven composite C-beam was produced. Three point bending test was then employed. The load-deflection curve and fracture surface were investigated. The results of the experiments showed that the flexural rigidity and the peak load increased with the web height or flange width of the specimen. For the same thickness of 2 mm, the specific flexural rigidity of the beam reaches its maximum, when the web height is approximately 5 cm , and the flange width is approximately 1 cm. The specific flexural load of the beam reaches its maximum, when the web height is approximately 3 cm and the flange width is approximately 1 cm. Therefore, we get an optimal cross-section of C-beam from experiments. From the experiments, the higher web specimen, the higher stress can be found on upper flange. Under the loading head, the sudden loss of stiffness was the result of the rupture of the material at the corners of the beam cross-section. This local loss of stiffness consequently changed the deflected shape and introduced torsion in the material underneath the loading head. For the specimen with lower web height, high stress can be found on the upper and lower flanges. The phenomenon was caused by the resin breakage. The A. Rothwell’s efficiency formulae was used to analyze for the C-beams of various cross-sections. Comparison of A.Rothwell formulae and experimental data showed that the web height of 1 cm has better accuracy. But the higher web was, the less accuracy of the analysis was. This may arise due to unwanted deformations of the beam as a result of bending-torsion and lateral buckling.
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