Prediction of the critical buckling load of grid-stiffened composite plates using Vibration Correlation Technique

Due to unique properties, grid-stiffened composite plates are used extensively in aviation, marine and automotive industry. In recent decades, several studies are done to predict the critical buckling load of grid-stiffened composite plates without breakdown or failure. One of the most important non-destructive methods, is Vibration Correlation Technique (VCT). The aim of this research is the prediction of the critical buckling load of grid-stiffened composite plates using VCT. For this purpose, nonlinear vibration analysis of grid-stiffened composite plates are firstly performed in different compressive loads using finite element software ABAQUS. In the next step, critical buckling load of grid stiffened composite cylinder shells is predicted using VCT. To validate the results of VCT, three grid-stiffened composite plates are fabricated using filament winding and hand lay-up method with same conditions and was placed under axial compression test. Finally, the critical buckling load is measured experimentally. The results show that the difference between the critical buckling load of VCT with experimental buckling load is less than 5%. This subject implies that VCT is suitable for prediction of critical buckling load of grid-stiffened composite plates with very high accuracy.