Search results for "Swelling stresse"

showing 3 items of 3 documents

Photoelastic stress analysis assisted evaluation of fracture toughness in hydrothermally aged epoxies

2014

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 s…

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.symptom
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Absorption kinetics and swelling stresses in hydrothermally aged epoxies investigated by photoelastic image analysis

2015

Abstract The present work proposes an experimental optical methodology able to measure the transient swelling stresses induced by the water uptake ageing of polymers. In particular, the work describes the implementation of a Photoelastic technique to quantify internal stresses arising during the hydrothermal ageing of cast epoxy samples. The material investigated is a model DGEBA/DDS epoxy system. Curing and post-curing cycles have been optimised in order to obtain a fully cured, high T g , and completely stress free initial condition. Rectangular beam samples were then left in a hydrothermal bath at 90 °C, and regularly monitored by gravimetric and photoelastic analyses. The quantitative e…

Absorption of waterMaterials sciencePhotoelastic stress analysiPolymers and PlasticsThermosetting polymerSwelling stresseSettore ING-IND/14 - Progettazione Meccanica E Costruzione Di MacchineDesorptionMaterials ChemistrymedicineComposite materialSettore ING-IND/15 - Disegno E Metodi Dell'Ingegneria IndustrialeCuring (chemistry)chemistry.chemical_classificationHydrothermal ageingPolymerEpoxyCondensed Matter PhysicschemistryMechanics of Materialsvisual_artThermosetting resinvisual_art.visual_art_mediumGravimetric analysisSettore CHIM/07 - Fondamenti Chimici Delle TecnologieSwellingmedicine.symptom
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Fracture Toughness of Hydrothermally Aged Epoxy Systems with Different Crosslink Density

2015

Abstract The present work investigates the fracture toughness behaviour of Single Edge Notched Bending (SENB) samples of epoxy systems subject to water uptake aging. Two epoxy systems with a significantly different Glass Transition Temperature, T g , are in particular considered: a typical commercial non-aeronautical grade resin matrix for composite applications, reaching a T g of 90 °C, and a DGEBA+DDS epoxy system achieving a T g of 230 °C.The materials have been conditioned by hydrothermal aging in a thermal bath at the temperature of 50 °C. TransmissionPhotoelastic Stress Analysisis carried outon SENB samples during water aging, monitoring the presence and evolution of swelling stresses…

Materials sciencePhotoelastic Stress AnalysiImage AnalysiComposite numberPhotoelastic Stress AnalysisStress (mechanics)Thermosetting ResinFracture toughnessEngineering (all)Fracture ToughnessHydrothermal AgingFracture Toughness; Hydrothermal Aging; Image Analysis; Photoelastic Stress Analysis; Swelling Stresses; Thermosetting Resin; Engineering (all)Composite materialEngineering(all)Image Analysis.General MedicineEpoxyDynamic mechanical analysisFracture ToughneSwelling StresseSwelling Stressesvisual_artvisual_art.visual_art_mediumFracture (geology)Gravimetric analysisGlass transition
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