Free-edge stresses in antisymmetric angle-ply laminates in extension and torsion

Abstract

The first-order shear deformation theory and the layerwise theory of laminated plates are employed to analyze the edgeeffect problem of an antisymmetric angle-ply laminate subjected to arbitrary combinations of extensional and torsional loads. The first-order theory is used for predicting the unknown constant parameters appearing in the reduced displacement field of elasticity which, on the other hand, signify the global behavior of the laminate. A layerwise theory is then utilized to determine the local interlaminar stresses within the boundary-layer regions of laminates. In order to closely examine the behavioral characteristics of interlaminar stresses, various numerical examples are presented for different antisymmetric angle-ply laminates under an axial force and a torque.

Free-edge stresses in general composite laminates

“…It is to be mentioned that, by means of comparison with the elasticity results, the accuracy and reliability of LWT have repeatedly been demonstrated in various studies and developments (see Refs. [25][26][27]35]). Also the computer programs prepared for the present work are validated by comparing the present results with the LWT results of Tahani and Nosier in Ref.…”

“…They used the layerwise theory (LWT) to investigate the interlaminar stresses near the free edges of the laminates. Based on the reduced elasticity displacement field of a long laminated composite plate, Nosier and Bahrami [26,27] studied interlaminar stresses in antisymmetric angle-ply laminates under extension and torsion. They also presented comprehensive examinations on various loading conditions at the ends of laminates.…”

“…Numerical studies conducted by the present authors indicate that, except for antisymmetric angle-ply laminates (see Refs. [26,27]) and unsymmetric cross-ply laminates (see Ref. [39]), the firstorder shear deformation theory (FSDT) of laminates, which is also known as the Mindlin-Reissner theory, is not so reliable for accurate prediction of the constant parameters appearing in Eq.…”

Interlaminar stresses of laminated composite beams resting on elastic foundation subjected to transverse loading

“…Tahani and Nosier [15] determined interlaminar stresses resulting from bending of rectangular cross-ply composite laminates by using a layerwise laminate theory. By using this theory, Nosier and Bahrami [16] analyzed the free edge stresses in antisymmetric angle-ply laminates in extension and torsion and Nosier and Maleki [17] studied the free edge stresses of composite laminates with general stacking sequences. Interlaminar stresses and free edge effects in a sandwich panel with flexible core and laminated composite face sheets under transverse loads were studied by Afshin et al [18,19].…”

A global-local higher order theory including interlaminar stress continuity and C0 plate bending element for cross-ply laminated composite plates

“…Among the possible approaches, three-dimensional models [1][2][3] as well as layerwise theories [4,5] are accurate enough for static and dynamic analysis of laminates. The disadvantage of these theories is their huge computational costs as the number of unknowns depends on the number of layers.…”