Summary: | 碩士 === 國立雲林科技大學 === 機械工程技術研究所 === 86 === Due to their high strength,high modulus, and lightweight,compositemate rials, no matter single-fiber system or interply hybrid system, havebeen exten sively applied in engineering. When the external compressive loadapplied to the composites with delamination reaches a critical value, bucklingmay occur around the delamination area.If the externalload iscontinuous toincrease until next critical value, delamination may start to grow and thecomposite fails. In additionto predict the critical buckling load by linearand nonlinearbuc kling analysis, the purpose of this project is to estimate the delaminationgrowth by combining postbuckling analysis and differentdelamination growthcriteria and toverify the above analysis by experiments. The materialsconsidered are single-fiber and interply hybridsystems, and the effectofstacking sequence will be discussed. Whatever single-fiber composites or hybrid composites, the results indicatethat buckling load decrease as the delamination length increase. If thedelamination near to the surface of thespecimen, buckling load will decrease.In hybrid composites, the buckling load will decrease as the number of interplyglass layer increase; As for the type of stacking sequences, the buckling loadof all-symmetric laminate is greater than part-symmetric laminate. In order topredict of delaminationgrowth,strain energy release rate component criterionor interlaminarstress criterion is precisely. When the delamination growthload islow,error will be controlled about 10%.However, the error will increaseas the delamination growth load increase.
|