MIXED FINITE ELEMENT FORMULATION FOR LAMINATED COMPOSITE CYLINDRICAL SHELLS BASED ON REFINED ZIGZAG THEORY

This paper presents a mixed finite element formulation to examine the linear static behavior of thin and moderately thick laminated composite cylindrical shells within the framework of the Refined Zigzag Theory (RZT). The RZT is very suitable for modeling thick and highly heterogeneous laminated composite structures without the need for the shear correction factor. The system's stationary condition is expressed by using the HellingerReissner principle. Finite element model employs four-noded quadrilateral elements with bilinear shape functions, meeting the C0 continuity requirements. The mixed finite element equations produce direct nodal displacements and stress resultants simultaneously. Comparisons and convergence analyses are performed by considering various lamination configurations and boundary conditions for validation purposes.