Dr. C. Kassapoglou continues the discussion about the buckling of a simply supported composite plate under biaxial loading. For simplicity it was assumed that the layup is symmetric, so the B-matrix could be neglected.

The next problem is the buckling of a simply supported composite plate under the uniaxial compression, with three simply supported edges and one free edge. A solution was found by solving the system with a random variable using Fourier series and comparing it with the exact solution to find an appropriate value.

Next the Galerkin method is used to determine the buckling load of a simply supported rectangular plate under pure shear load. The load can be determined by solving the generalized eigenvalue problem.

Castigliano’s method of energy minimization is used to solve the case for a simply supported plate under combined loading. After solving the standardized eigenvalue problem the answer was obtained in terms of buckling load. Prof. C. Kassapoglou compares various solution methods for different types of loads including transverse shear effects, pure compression and the pure shear.  Lastly the buckling interaction curve was presented.

In the final part the lecturer gives the solutions for various cases of loading and  boundary conditions for the buckling of plates and discusses the effect of boundary conditions.