Analysis of an initially stressed hybrid plate based on a higher-order theory

The natural frequencies and buckling loads of hybrid Al/GFRP/Al plates in a general state of nonuniform initial stress are investigated. The governing equations are based on Lo’s higher-order shear deformation theory and derived using the average stress method. The initial stress is taken as a combination of uniaxial extensional stress and pure bending. The effects of various parameters on the natural frequencies and buckling loads are studied. The results show that present theory gives acceptable estimates of the buckling load and vibration frequency. The vibration frequency and buckling load are sensitive to the number of layers of GFRP, stacking sequence and thickness ratio of GFRP to aluminum, and the state of the initial stresses.