Numerical investigation of stress states in buckled laminated composite plates under dynamic loading

Abstract The composite structures of super-/hyper-sonic vehicles can experience thermal or mechanical buckling due to aero-thermal-structural coupling. These buckled structures are susceptible to dynamic snap-through, which could possibly accelerate damage progression. This paper is part of a long-term project investigating structural dynamics and damage progression for composite structures under these extreme environments. The work herein focuses on analyzing the stress histories of thin laminated composite plates under various combinations of structural and forcing conditions including buckling and snap-through. A geometrically nonlinear model is developed in-house using MATLAB by incorporating the first-order shear deformation theory, von Karman strains, and enhanced assumed strain elements. The global dynamic behaviors of this model in the post-buckled regime are first validated using experimental and numerical data. The impacts of buckling and snap-through on the internal stress states are then investigated. The results reveal that composite structures can experience significant stress amplification under such extreme environments. The potential impact of this phenomenon on fatigue is also discussed.