Vibration Analysis of [αββγααβ]_r Type Laminated Composite Plates Using Invariant and Correction Factor

불변량(不變量)과 수정계수(修正係數)를 사용(使用)한 [αββγααβ]_r 적층부합판(積層復合板)의 진동해석(振動解析)

For a large scale civil and architectural structures, mainly steel, concrete and aluminum have been used and weight and corrosion of materials became a major concern. Designing with composite materials is very much complicated. Simple classical theory may yield good results for selecting "initial" sections for preliminary design. D. H. Kim proposed to use the quasi-isotropic constants by Tsai for the preliminary design of the composite primary structures for the civil construction. Also he made simple equation using correction factor. In this paper, the simple formulas developed by D. H. Kim to obtain "exact" values of the natural frequencies of [ABBCAAB]r laminate are compared with Whitney's equations. Also natural frequencies of the plate with varying aspect ratios and reinforcing fiber orientations, are compared with natural frequencies of bean. This work can be a guideline to obtain data in many other cases.