ISSN:
1573-2738
Keywords:
damage
;
durability
;
influence of environmental conditions
;
laminates
;
reliability
;
unidirectional lamina
;
viscoelasticity
;
viscoplasticity
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Polymers are time-dependent materials. Polymer matrix compositesbehave as viscoelastic-viscoplastic anisotropic continua. Theirthermomechanical characteristics are not only time-dependent, but arestrongly influenced by the variations of the environmental conditions(temperature, moisture diffusion, radiation, etc.). This concerns notonly the stiffness but also the strength characteristics, related to thedamage development. Due to the composite nature, the number of potentialdamage sources is high and the damage development has to take intoaccount all the interactions between simple mechanical loading modes,with or without, changing environmental conditions. Following anon-linear viscoelastic-viscoplastic analysis, based on the Schaperyequations and a Zapas–Crissman functional, the stiffness degradation isobtained based on short-term creep and creep-recovery measurements atdifferent stress levels and different temperatures. A damagecomponent is added to the viscoelastic-viscoplastic model in order toaccount for damage development and associated strength degradation.Results obtained in the transverse direction of an unidirectionalgraphite-epoxy composite are presented. The extension to completelaminates with different stacking sequences is discussed. An assumptionon the interlaminar behaviour must be introduced in order to take intoaccount the important damage source not considered in classical laminatetheories.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1009829926708
Permalink