M. Di Sciuva et U. Icardi, Numerical assessment of the core deformability effect on the behavior of sandwich beams, COMP STRUCT, 52(1), 2001, pp. 41-53
A modified zig-zag technical theory suitable for the accurate analysis of m
ulti-layered composite beams accounting for the full 3D stress state has be
en recently developed by one of the authors [U. Icardi, A three-dimensional
zig zag theory for analysis of thick laminated beams. In: Modern Trends in
the Theory and Behavior of Structures Symposium ASME 1999 Summer Conferenc
e, Blacksburg, Virginia, USA, 27- 30 June 1999]. In order to satisfy the tr
ansverse shear and the transverse normal stress and stress gradient continu
ity requirements at the laminae interfaces through appropriate jumps in the
strains, the theory features a piecewise third-order approximation for the
in-plane displacement and a fourth-order approximation for the transverse
displacement across the thickness. In the present paper, the capability of
such a theory to predict the displacement and stress distribution across th
e thickness of sandwich beams is numerically assessed. This is done by comp
aring present estimates with the Pagano's elasticity solution [N.J. Pagano,
J. Compos. Mater. 3 (1969) 398-411] for simply-supported, sandwich beams w
ith cross-ply faces, loaded by a sinusoidally distributed transverse load.
Additional results are presented that evidence the effects played by an enh
anced core's deformability, or by stiffening the faces. It is seen from the
numerical results presented the need for including non-classical complicat
ing effects, to accurately predict the stress and displacement distribution
s across the thickness, and even for the estimation of the overall response
. These comprise modeling of the transverse normal strain and transverse sh
ear deformation; fulfillment of the transverse shear stress and transverse
normal stress and stress gradient continuity conditions at interfaces; mode
ling of the cross-section warping. The numerical results show a good predic
tive capability of the present model with using one sublaminate for each la
yer and for the core, except for the case of faces with drastically differe
nt elastic moduli, which require use of more sublaminates. (C) 2001 Elsevie
r Science Ltd. All rights reserved.