Dynamic Characteristics of Composite Thin-Walled Beams with a Chord-Wise Asymmetric Cross-Section: II. Multi-Cell

시위 방향 비대칭 단면의 복합재료 박벽보의 동특성 연구: II. 다중-셀

Abstract

Subsequently, Part I [1], which was about the single-cell model, a composite thin-walled beam with a multi-cell of chord-wise asymmetric cross-section, was selected in this study. Moreover, the theoretical dynamic characteristics of the model were analyzed. For this analysis, mathematical modeling was performed by considering the warping restraint effects, transverse shear effects, taper ratio and cross-section ratio. Similar to part I, the mass, stiffness coefficients and Eigen frequencies of the multi-cell section considered were investigated. In particular, the comparison between the multi-cell and single-cell sections and the effects of the cross-section ratio and taper ratio of the model on the Eigen frequencies were analyzed. However, the results compared when the asymmetry of the section was considered and warping function were not corrected.

이번 연구에서는 앞서 Part I [1]에서 수행한 단일-셀(single-cell) 모델에 이어, 시위 방향으로 비대칭성 단면을 가지는 다중-셀(multi-cell) 복합재료 박벽보(thin-walled beam) 모델을 선정하여, 단면의 형상에 대한 이론적인 동특성을 해석하였다. 이를 위해 와핑 구속 효과와 전단 변형 효과, 보의 테이퍼비와 단면비 등을 고려하였다. Part I에서와 마찬가지로 다중-셀 단면의 질량 및 강성 계수와 고유 진동수 등의 특성을 조사하였다. 특히, 다중-셀과 단일-셀 단면을 비교하고, 다중-셀 단면의 고유 진동수에 미치는 테이퍼비와 단면비의 영향을 비교 분석하였다. 또한, 단면의 비대칭성과 와핑 함수를 보정하지 않은 경우에 대해 그 결과를 비교하였다.

Fig. 1 Shear flow distribution in the R-th cell

Fig. 2 A Chordwise asymmetric model (3-cell)

Fig. 3 Symmetrical model for comparison

Fig. 4 Stiffness coefficients for CUS

Fig. 5 Stiffness coefficients for CAS

Fig. 6 Eigenfrequencies of 3-cell vs. 1-cell models for CUS

Fig. 7 Eigenfrequencies of 3-cell vs. 1-cell models for CAS

Fig. 8 Eigenfrequencies of asymmetric (variant) vs. symmetric (base) models for CUS

Fig. 9 Eigenfrequencies of asymmetric (variant) vs. symmetric (base) models for CAS

Fig. 10 Eigenfrequencies for CW and NCW cases for CUS

Fig. 11 Eigenfrequencies for CW and NCW cases for CAS

Fig. 12 Eigenfrequencies for taper ratio for CUS

Fig. 13 Eigenfrequencies for taper ratio for CAS

Fig. 14 Eigenfrequencies for thickness ratio for CUS

Fig. 15 Eigenfrequencies for thickness ratio for CAS

Table 1 Mass coefficients b_j for CUS & CAS

Table 2 Stiffness coefficients a_ij for CUS

Table 3 Stiffness coefficients a_ij for CAS