A study of the thermal buckling behavior of a circular aluminum plate using the digital image correlation technique and finite element analysis

• A famous thermal buckling problem of a plate was revisited with an optical method.
• 3-Dimensional full field deformation could be measured at different temperatures.
• A circular polarized light filter could reduce measurement error.
• DIC technique is promising for solving thermal buckling problems.

In this study, the thermal buckling behavior of a circular aluminum plate that results from thermal loading was investigated using a digital image correlation (DIC) technique. The aluminum plate was placed in a titanium ring and the structure was heated from room temperature 25 °C to 160 °C. Due to the differences in the coefficients of thermal expansion (CTEs) between aluminum and titanium, the aluminum plate buckles at a certain temperature. The buckling temperature was determined from the full-field deformation shape and temperature-displacement curve that were obtained using the DIC-based ARAMIS® software. In order to obtain an appropriate full-field deformation, a polarized light filter was used to reduce the out-of-plane displacement error, which is an unavoidable error in the experiment. Using this method, the standard deviation of the z directional displacement was reduced from ±3.14 μm to ±2.70 μm. In addition, the results demonstrated that the measured buckling temperature was close to the theoretical buckling temperature of the circular plate in a simply supported boundary condition. In order to verify the proposed measurement method, a finite element analysis of the structure was performed using the ABAQUS software. The results of the DIC-based measurement and finite element analysis were in good agreement regarding the deformation curve tendency. The buckling temperature from the finite element method (FEM) was slightly larger than that from the experimental results due to the initial imperfections of the aluminum specimen. These results provide a good method for studying thermal buckling for the design and analysis of engineering structures in diverse fields such as aerospace engineering, oil refineries, and nuclear engineering.

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