Premium
Influence of the dynamic stress intensity factor on cyclic crack propagation in polymers
Author(s) -
Radon J. C.
Publication year - 1973
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1973.070171123
Subject(s) - materials science , fractography , fracture toughness , stress intensity factor , composite material , fracture mechanics , ultimate tensile strength , paris' law , cyclic stress , crack closure , fracture (geology) , polymer
A relationship of the form$$ {{d\left( {2a} \right)} \mathord{\left/ {\vphantom {{d\left( {2a} \right)} {dN}}} \right. \kern-\nulldelimiterspace} {dN}} = \alpha \beta \lambda ^n $$ developed for the evaluation of cyclic crack propagation in tensile/tensile fatigue was used to investigate the effects of frequency on fatigue crack growth. In order to establish the correlation between stress intensity K and dK/dt at 21°C, dynamic fracture toughness tests were performed on a range of polymers. It was shown that, in general, fracture toughness increased with the strain rate applied. Consequently, a decreasing trend in the crack growth rate was observed in the fatigue tests performed at higher frequencies. The occurrence of other localized peaks of fracture toughness recorded at various temperatures and strain rates is described. The fractography of fatigue surfaces is also discussed.