Experimental and numerical investigation of nonlinear dynamics and snap-through boundaries of post-buckled laminated composite plates

Thermally-buckled composite panels of high-speed aircraft may experience dynamic snap-through due to aerodynamic loading, which can accelerate damage growth. Therefore, understanding post-buckled dynamic responses can be an important step in developing reliable simulation tools to predict consequent damage growth. To address this issue, this work experimentally and numerically investigates nonlinear dynamics and snap-through boundaries of post-buckled laminated composite plates under various harmonic loading scenarios. Full-field and single-point sensing methods are used to explore the spatio-temporally complex behavior and parameter sensitivity of post-buckled plates. Based on the full-field data of the specimen's static buckled shape, a numerical model was generated using an in-house finite element code, which was written in MATLAB based on the classical laminated plate theory along with nonconforming (semi-C1 continuity) cubic Hermite elements and Rayleigh damping. The simulation results including numerical snap-through boundaries showed an excellent agreement with the experimental observations, thereby providing robust validation of the model. The experimental and numerical data obtained through this work provide a benchmark for the development of an efficient dynamic model for simulation of damage growth in composite structures subjected to high-frequency dynamic loading.