Thermal buckling of composite laminates with elastic boundaries

Abstract The investigation of thermal buckling in composite laminates holds significant theoretical and practical implications. For the commonly encountered rectangular thin plate structures in engineering, this study aims to explore their buckling characteristics under thermal loads in arbitrary elastic boundary conditions. To achieve this, a method based on the principle of minimum potential energy for calculating the buckling load during elastic instability is presented. Initially, transverse constraint springs and rotational constraint springs are set at the four boundaries of the plate structure model, with the stiffness values of these two types of elastic springs designated to simulate arbitrary elastic boundary conditions. The improved Fourier series is employed to address potential discontinuities in the boundary derivatives of displacement functions that may arise with the classical Fourier series form. Subsequently, the potential energy expression for the rectangular plate system is established. By combining this with the principle of minimum potential energy, a system of linear equations is derived through partial differentiation of the unknown Fourier coefficients. Finally, the critical buckling load and other parameters of the rectangular plate are obtained, with reasonable values for the spring stiffness under different boundary conditions provided. The critical buckling temperatures derived from the proposed method are compared with those obtained via finite element analysis. The results indicate that the buckling loads obtained using this method align closely with those from finite element analysis, affirming the validity and convergence of the research methodology. Highlights This study investigates the thermal buckling of composite laminate plates with elastic boundary conditions. Improved Fourier series techniques are employed to analyze thermal buckling in these laminates. The impact of intermediate stiffness on the thermal buckling response of composite materials is examined.