6533b7d1fe1ef96bd125c346
RESEARCH PRODUCT
Photoelastic stress analysis assisted evaluation of fracture toughness in hydrothermally aged epoxies
Andrea ToscanoSabina AlessiGiuseppe PitarresiGiuseppe SpadaroM. Di FilippoMichele Scafidisubject
ToughnessMaterials scienceAbsorption of waterlcsh:Mechanical engineering and machinerylcsh:TA630-695Stress (mechanics)Thermosetting ResinSettore ING-IND/14 - Progettazione Meccanica E Costruzione Di MacchineFracture toughnessFracture Toughnessmedicinelcsh:TJ1-1570Hydrothermal AgingComposite materialPhotoelasticityFracture Toughness; Hydrothermal Aging; Thermosetting Resin; Swelling Stresses; Photoelastic Stress Analysis.Mechanical EngineeringEpoxylcsh:Structural engineering (General)Fracture ToughneSwelling StresseSwelling StressesMechanics of Materialsvisual_artvisual_art.visual_art_mediumPhotoelastic Stress Analysis.Gravimetric analysisSettore CHIM/07 - Fondamenti Chimici Delle TecnologieSwellingmedicine.symptomdescription
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.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2014-09-10 |