Summary: | 碩士 === 國立雲林科技大學 === 機械工程系 === 106 === At present, carbon fiber composite material can replace metals with their high strength and light weight, but its impact resistance is low. In this paper, the damage caused by external force is concerned, and the most common type of damage, delamination, is discussed. When delamination occurs, the strength of the carbon fiber composite material will be reduced. With simple experiment and analysis, one can discuss the delamination. The composite plate consisting of PU resin and woven carbon fiber is fabricated by vacuum assistant resin transfer molding. By using finite element analysis of LS-DYNA, the delamination area is compared to the experimental C-scan result.
In this study, by using different energies, three damage cases, which are penetration、non-penetration and barely visible impact damage, are created. The peak load, the damage mode, and the delamination area are compared between the simulation and the experiment. The damage situation on the back side of the impact specimen is same as that from the simulation. The peak load of the analysis for the case of barely visible impact damage has error 2.4% with respect to the experiment. The error for the non-penetration case is 9.5%, and that for the penetration case is 3%.
From experiment, the delamination area for the case of barely visible impact damage is 237.78mm2 with 15.3% difference with the analysis. The delamination area for the non-penetration case is 624.14mm2 with 6.6% difference with the analysis. The delamination area of the penetration case is 814.33 mm2 with error5.1% difference with the analysis. For these results, the analysis has reliable results, and it can be used to predict the damage of carbon fiber composites.
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