Creep characterization of vinyl ester nano-composites using the digital image correlation technique Conference Paper uri icon

abstract

  • The tensile creep behavior of composites prepared from a vinyl ester resin (Derakane 441 400) with oxidized vapor-grown carbon nanofibers (VGCNFs) was characterized for composites containing 0.25 parts of fiber per hundred parts resin (phr), 0.5 phr, and 0.75 phr. These nano-composites were fabricated by high shear mixing, casting, and curing the test articles in an open face mold under nitrogen for a prescribed heating and post-curing cycle. Short term creep/creep recovery experiments were conducted to obtain the viscoelastic response at two stress levels (60% and 70% of the ultimate tensile strength) for each VGCNF weight fraction and for each of four temperatures (~24oC, 40oC, 60oC, and 80oC). These temperatures are well below the average glass transition temperature (135C) of the cured neat vinyl ester resin. A non contact digital image correlation technique was used to measure the creep strains in the longitudinal and transverse directions simultaneously. The creep compliances were calculated from the generalized 3-D viscoelastic constitutive equation with a Prony series representation. The effect of the VGCNF weight fraction on the ultimate tensile strength and creep compliance of the neat vinyl ester polymer and the nano-composites is discussed. The creep compliance decreased as the VGCNF weight fraction was increased. At the higher temperatures of 60C and 80C, the transverse creep compliance of the 0.25 phr nano-composite was determined to be greater than the creep compliance of the vinyl ester polymer.

author list (cited authors)

  • Drake, D. A., Simsiriwong, J., Sullivan, R. W., Toghiani, H., Lacy, T. E., & Pittman, C. U.

publication date

  • December 2012