Premium
Fatigue crack propagation behavior of cellulose esters
Author(s) -
Moskala Eric J.,
Pecorini Thomas J.
Publication year - 1994
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760341804
Subject(s) - crazing , materials science , composite material , shear (geology) , fracture mechanics , plasticizer , strain rate , polymer
Abstract The effect of plasticizer concentration on fatigue crack propagation (FCP) rate in cellulose acetate‐propionate (CAP) was determined. Compact tension specimens were machined from 6.2 mm‐thick injection molded plaques and tested on an MTS servohydraulic testing machine using a sinusoidal waveform with a frequency of 1 Hz. Two FCP mechanisms were identified: a crazing mechanism, which dominated at low values of stress intensity factor range, Δ K , and a shear yielding mechanism, which dominated at high values of Δ K . The value of Δ K at the onset of the transition from the crazing mechanism to the shear yielding mechanism was a function of plasticizer concentration, and therefore yield strength of the CAP. The transition in crack propagation mechanism created a V‐shaped feature on the fracture surface, which could be used to weight the contributions from the two crack propagation mechanisms to the overall FCP rate.