Dynamic stiffness formulation for composite Mindlin plates for exact modal analysis of structures. Part II: Results and applications

The dynamic stiffness method for composite plate elements based on the first order shear deformation theory is implemented in a program called DySAP to compute exact natural frequencies and mode shapes of composite structures. After extensive validation of results using published literature, DySAP is subsequently used to carry out exact free vibration analysis of composite stringer panels. For each example, a finite element solution using NASTRAN is provided and commented on. It is concluded that the dynamic stiffness method is more accurate and computational efficient in free vibration analysis than the traditionally used finite element method.

► Dynamic stiffness method (DSM) developed in Part I is extensively validated.
► Comparison is made with FEM results using NASTRAN.
► Exact modal analysis of composite stringer panels is carried out for the first time.
► New DSM is more accurate and computationally efficient than FEM for modal analysis.
► New DSM can be used for design, optimisation and to validate FEM.