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Process-induced stress relaxation analysis of AS4/3501-6 laminate

Book ·
OSTI ID:237738
;  [1]
  1. Univ. of Illinois, Urbana, IL (United States). Dept. of Aeronautical and Astronautical Engineering

In this study the process-induced stresses for AS4/3501-6 cross-ply laminates were analyzed. To formulate the constitutive equations, several stress relaxation tests were performed for 3501-6 epoxy resin at different degree of cure states. The master curve and shift function for each degree of cure case were obtained by time-temperature superposition. On the basis of this data, the thermorheologically complex behavior of 3501-6 epoxy resin was modeled. The resin model was then used to formulate the constitutive equations for AS4/3501-6 composite. A finite element method was used to calculate the interlaminar stress relaxation at the free edge of AS4/3501-6 cross-ply laminates during cooldown from the cure temperature. Significant reduction of residual stress was found to occur at a modest (2.5 C/min) cooldown rate.

OSTI ID:
237738
Report Number(s):
CONF-9510177--; ISBN 1-56676-376-2
Country of Publication:
United States
Language:
English