Nw. Hagood et A. Pizzochero, RESIDUAL STIFFNESS AND ACTUATION PROPERTIES OF PIEZOELECTRIC COMPOSITES - THEORY AND EXPERIMENT, Journal of intelligent material systems and structures, 8(9), 1997, pp. 724-737
This work attempts to characterize and model the effective stiffness a
nd actuation properties of active composite materials under high uniax
ial tensile loads. The motivations for this undertaking are to obtain
effective material properties as damage accumulates in the active elem
ent and to identify the mechanisms affecting stiffness and actuation t
o improve the material. A unified model with predictive capability for
overall laminate effective material properties was developed. Key mod
el assumptions include a constant linear elastic fiber recovery length
and a Weibull form for fiber strength. A one dimensional shear lag mo
del was employed to characterize the load transfer between the composi
te's layers. In order to validate this model several experiments were
conducted on interdigitated electrode piezoelectric fiber composites e
mbedded in E-glass laminae. Actuation data were obtained by performing
active tests: specimens were subjected to increasing tensile loads an
d measurements of actuation under load were taken at selected strain l
evels. Stiffness data was collected during actuation tests. Very good
correlation was demonstrated in most cases between predicted behavior
and experimental results.