Applications in Engineering Science (Sep 2021)

Spatial and temporal changes in physical properties of epoxy during curing and their effects on the residual stresses and properties of cured epoxy and composites

  • Anastasia H. Muliana

Journal volume & issue
Vol. 7
p. 100061

Abstract

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This study presents modeling and analyses of epoxy curing incorporating gradual changes in the thermal and mechanical properties of epoxy due to the cross-linking process. The model includes an exothermic process from the cross-linking, heat conduction across the specimen, and deformations of the specimen during curing. The study examines the influence of volumetric changes from the thermal expansion and shrinkage effects and gradual changes in the thermal and viscoelastic properties of epoxy on the deformation of the epoxy and the formation of stresses. The effects of curing temperatures and pressure on the formation of stress during curing and residual stress after complete curing are also investigated. The temporal and spatial changes in the physical properties of epoxy during curing affect the elastic modulus of the cured epoxy specimens. Furthermore, this study also investigates the existence of fiber reinforcements on the curing process of unidirectional fiber composites comprising carbon fibers in an epoxy matrix. A unit-cell model is generated and used to examine the formation of residual stresses in the composites and their influences on the mechanical properties of the composites.

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