Nn. Huang et al., THE EFFECT OF PHYSICAL AGING ON THE VISCOELASTIC RESPONSE OF CROSS-PLY LAMINATES TO INPLANE COMPRESSION, Zhongguo gongcheng xuekan, 21(2), 1998, pp. 159-170
The viscoelastic behaviors of simply-supported, cross-ply laminates wi
th a physical aging phenomenon are examined. The laminates considered
are under uniaxial in-plane compression and have various amplitudes of
initial imperfection. Laminae exhibit different aging shift rates for
the creep responses to the axial and shear loadings. The effective ti
me theory is employed to construct the stress-strain relations. The st
ress function is obtained by solving the compatibility equation by the
use of the Laplace transform and a numerical integration scheme. Defl
ections are calculated from the moment equation by the Galerkin method
in conjunction with the numerical integration. Numerical results of c
reep deflections, edge shortenings and stress resultants for graphite-
reinforced thermoplastic and glass-reinforced thermosetting laminates
are presented. The effects of physical aging, pre-loading aging time,
and the amplitude of imperfection on the creep responses are illustrat
ed in the numerical examples.