Classical and Improved Theories

Abstract

In this chapter, the theoretical background for two commonly used structural theories for the modelling and analysis of laminates and sandwiches is considered, namely the classical laminate theory and the first-order shear deformation theory. The classical laminate theory (CLT) and the first-order shear deformation theory (FSDT) are the most commonly used theories for analyzing laminated or sandwiched beams, plates and shells in engineering applications. The CLT is an extension of Kirchhoff’s classical plate theory for homogeneous isotropic plates to laminated composite plates with a reasonable high width-to-thickness ratio.