Abstract:Transverse shear deformation at each layer must be considered accurately when buckling loading is analyzed for composite sandwich structures. The reason is that there is much difference of mechanical properties between each layer. A four-node plate element based on Reddy’s Layerwise plate theory is developed in this paper for buckling analysis of composite sandwich structures. The first-order shear deformation theory is applied at each layer. Mixed interpolation of tensorial component is used to fix the problem of shear locking. Three numerical examples were analyzed and compared to the results in open literatures. The results show that the proposed element can discretely consider the mechanical properties of each layer; the accuracy of the proposed finite element is good; the results fit well with the results based on three dimensional elastic theory or high-order plate theory when the plate is modelled by several layers elements and the results fit well with the results based on first-order shear deformation plate theory when the plate is modelled by single layer elements