Transverse normal stress effects in multilayered plates

An evaluation of transverse normal stress sigma(zz) effects in multilayered plate modeling is given in this paper. Mired theories with continuous inte rlaminar transverse shear and normal stresses have been formulated on the b asis of Reissner's theorem (Reissner, 1984). The case in which the number o f the displacement variables preserves independence by the number of consti tutive layers, N-l, has been investigated. Classical models based on standa rd displacement formulations have been discussed for comparison purposes. T he analysis of transverse stress effects has been conducted by allowing a c onstant, linear, and higher-order distribution of the transverse displaceme nt components in the plate thickness directions. Related two-dimensional mo dels are compared for the static response of symmetrically and unsymmetrica lly layered, simply supported plates made of isotropic as well as orthotrop ic layers. The conducted numerical investigation and comparison with availa ble results have above all led to the following conclusions. The possibilit y of including sigma(zz) makes the used mixed theories more attractive that other available modelings. sigma(zz) plays a fundamental role in thick lam inate plates analysis. Such a role increases in transversely anisotropic mu ltilayered plate analysis. With an increase of the plate thickness, a very accurate description of sigma(zz) requires modelings whose number of indepe ndent variables depends on N-l.