Photoelastic stress analysis assisted evaluation of fracture toughness in hydrothermally aged epoxies
The present work has investigated the fracture toughness of a model DGEBA epoxy system subject to Hidro-Thermal aging. A Photoelastic Stress Analysis technique has been implemented, showing the evolution of stresses arising throughout the water uptake process due to the non-uniform swelling of the...
Saved in:
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Gruppo Italiano Frattura
2014-10-01
|
| Series: | Fracture and Structural Integrity |
| Subjects: | |
| Online Access: | http://www.gruppofrattura.it/pdf/rivista/numero30/numero_30_art_17.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | The present work has investigated the fracture toughness of a model DGEBA epoxy system
subject to Hidro-Thermal aging. A Photoelastic Stress Analysis technique has been implemented, showing the
evolution of stresses arising throughout the water uptake process due to the non-uniform swelling of the
material. Gravimetric and Dynamic Mechanical Thermal Analyses have further complemented the
characterization, showing the onset of plasticization effects with aging. The correlation of all previous
characterizations has allowed to conclude that an increase of KIC fracture toughness is obtained at the fully
saturated condition. In particular Photoelasticity has also revealed the onset of relevant swelling induced stresses
during the first stages of water absorption, leading to an increase of fracture toughness due to compressive
stresses settling near the crack tip. A stress free condition is instead reestablished at the later stages of
absorption, suggesting that the increased toughness of the saturated material is an effect of the modifications
induced by aging on the polymer structure. |
|---|---|
| ISSN: | 1971-8993 1971-8993 |