structures. figure 7.1 are for laminates consisting of plies of the same material.For by enclosing the set of angles in parentheses.The examples shown in overbar.Sets of ply angles that are repeated in the laminate are identified having an odd number of plies,the center ply angle is denoted by an subscript on the appropriate ply angle.In the case of symmetric laminates plies having the same orientations can be described by using a numerical be described by listing only the ply angles for the top half of the laminate and by using the subscript "s"outside the brackets,and that adjacent shown by the examples in figure 7.1.Note that symmetric laminates can top surface to the bottom surface and enclosed in square brackets,as code is that ply angles,separated by slashes,are listed in order from the orientation code has evolved in the composites literature.The basis of the nations of ply orientations and stacking sequences in laminates,a laminate Because of the need for adequate description of many possible combi- laminate strength are also discussed. prediction of thermal and residual stresses, interlaminar stresses,and that may occur in laminates.Other aspects of laminate analysis,such as (CLT),which makes it possible to analyze the complex coupling effects followed by a discussion of the more general Classical Lamination Theory ering a simplified theory of laminated beams in pure flexure.This will be In this chapter,the analysis of laminates will be introduced by consid- struction considerably enhance the design flexibility inherent in composite ply orientations,and ply-stacking sequences offered by laminated con- in a structural unit.The virtually limitless combinations of ply materials, laminae or plies oriented in the desired directions and bonded together are more likely to be in the form of laminates consisting of multiple element because of its poor transverse properties.Composite structures unidirectional lamina alone is generally not very useful as a structural development of theories for the analysis of composite structures,the While an understanding of lamina mechanical behavior is essential to the 7.1 Introduction Analysis of Laminates