Using closed-section ribs as longitudinal stiffeners have been proven to be an effective system for axially compressed members, however, studies on the application of these on laminated composite shell are insufficient. Thus, this study aims to evaluate the buckling behavior of the laminated composite shell when closed-section ribs were applied as longitudinal stiffeners. The effect of the rotational stiffness of the closed-section ribs on the buckling modes and strengths will be determined in this paper. The three-dimensional finite element modeling were set up using ABAQUS and a series of eigenvalue analysis were conducted, applying eight layers of the layup [(0°)4]s, [(45°/-45°)2]s and [(0°/90°)2]s on the orthotropic plates. Through the parametric studies, the increasing effect on the elastic buckling strengths due to the rotational stiffness are numerically verified, and the buckling strength of a longitudinally stiffened shell with a laminated composite material were compared with that of the isotropic material.

ABSTRACT
 1. Introduction
 2. Numerical Analysis
  2.1 Analytical Model
 3. Analysis Results
 4. Conclusion
 References

• Arriane Nicole Andico(한밭대학교 건설환경공학과)
• 이상형(한밭대학교 건설환경공학과) | Lee Sang-Hyeoung
• 최병호(한밭대학교 건설환경공학과) | Choi Byung-Ho