Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 30 for “"interfacial fracture"”.
-
A chemical and mechanical evaluation of interfacial fracture in dicyandiamide cured epoxy/steel adhesive systems
The interfacial fracture performance of dicyandiamide cured epoxy/steel adhesive systems was thoroughly investigated. Fracture mechanics based testing was utilized to study several variables which were believed to influence the epoxy/steel interphase region, specifically the elasomeric toughener …
-
Characterization of the Interfacial Fracture of Solvated Semi-Interpenetrating Polymer Network (S-IPN) Silicone Hydrogels with a Cyclo-Olefin Polymer (COP)
… experimental, analytical, and numerical methods. Interfacial fracture data was collected through the application of the wedge test, a relatively simple test allowing for the measurement of fracture properties over time in environments of interest. In this case, the test was performed at discrete …
-
Fracture path transitions in peels tests of medium carbon steel spot welds
Fracture path transition, from interfacial fracture to a pulled button, in peel tests of spot welds in SAE 1039 steel was evaluated to determine the controlling material properties. Welds were tested in the as welded condition and after tempering at various temperatures to develop a range of …
-
Adhesion Strength of Cordierite Bulk Coatings on Molybdenum Substrates
… because of ease in testing and availability of fracture mechanics interpretations of test data. The interfacial fracture toughness was determined from indentation load vs. crack length data by examining the residual stress and critical buckling load of the ceramic coatings. The interfacial …
-
HYGROTHERMALLY-INDUCED DELAMINATION AND CRACKING IN PLASTIC IC PACKAGES
… may exist in bonded interfaces. These small interfacial defects induce very high stress concentrations around the defects leading to debonding and delamination growth. If the total stress intensity factor generated by the loading due to the hygrothermal stresses and steam pressure is higher …
-
Mechanochemical activation at solid interfaces
… at the molecular level and macroscopic interfacial fracture toughness at SAM-modified interfaces. Characterization and application of surface chemistry changes resulting from activation of force-sensitive mechanophore modified interfaces remains largely unexplored. In this dissertation, …
-
Effects of Surface Microstructure on the Strength of Adhesively Bonded Structures
… on the influence of surface roughness on the fracture resistance of an aluminum-epoxy interface. A layered double cantilever beam (LDCB) specimen was chosen for this experiment. The LDCB specimen was debonded by peeling off the epoxy layer from the aluminum substrate using a steel wedge. …
-
Quantitative evaluation of thin film adhesion using the probe test
… film epoxy polymer coated silicon system. The interfacial fracture energy (Gc) (or critical strain energy release rate) has been used as a quantitative measure of adhesion for the given adhesive coating/substrate system. The probe test experiments were conducted using an optical microscope and …
-
Measurement of Interfacial Adhesion in Glass-Epoxy Systems Using the Indentation Method
… Experimental observations and measurements of interfacial adhesion in glass-epoxy systems are described in this thesis. A comparison study of how different glass treatments affect adhesion was also conducted: smooth versus rough, clean versus unclean, stressed versus non-stressed. The Oliver …
-
Role of segregation and precipitates on interfacial strengthening mechanisms in metal matrix composites when subjected to thermo-mechanical processing
… conditions in order to attain higher values of interfacial fracture strength, due to precipitation hardening and segregation mechanisms, also exhibited enhanced bulk mechanical and fracture resistant properties.</p> <p>An analytical model to predict the interfacial fracture strength in the …
-
Finite Element Analysis Of A Test Specimen For Strength Of A Co-polymer Layer At A Bone-implant Interface
… (MMA), so that it can be applied as an interfacial layer between bone cement and steel implants to improve their performance and life. Finite element (FE) analysis techniques are used to assess the behavior of the interface layer under static and dynamic loading conditions. The material …
-
Quantitative and consistent tests for interlayer adhesion in laminated glass
… of samples: low and high adhesion. Stress and fracture analysis was conducted using the finite element method. The numerical analysis was first validated against simple strength of materials analyses and the measured load deflection response. The numerical analysis then provided the variation …
-
Mechanical Characterization of Coating-Interconnect Interfaces and Anode-Electrolyte Interfaces for Solid Oxide Fuel Cells
… of the bend specimen are used to quantify the interfacial shear strength from a shear lag model. In addition, the onset strain of coating spallation is incorporated in an energy based fracture mechanics model to obtain the interfacial fracture energy. Images from scanning electron microscopy …
-
Development of an enhanced microstructure–level machining model for carbon nanotube reinforced polymer composites using cohesive zone interface
… and the polymer phase, thereby assuming perfect interfacial bonding. However, subsequent experimental investigations revealed that the failure mechanism during machining is primarily governed by the CNT–polymer interface. Since the strength of the CNT–polymer interface is critical to the load …
-
Self-Assembly of Pullulan Abietate on Cellulose Surfaces
… biocomposite that exhibits a high work of fracture, making it an ideal model for multiphase man-made materials. Typically, man-made composites demonstrate interfacial fracture at failure due to abrupt transitions between neighboring phases. This phenomenon does not occur in wood because …
-
Molecular tailoring of interfaces for thin film on substrate systems
… undergo thermo-mechanical cycling, which induces interfacial delaminations leading to failure of the overall device. The ability to tailor interfacial properties at the molecular level provides a mechanism to improve thin film adhesion, reliability and performance. This dissertation presents the …
-
Characterization of the Viscoelastic Fracture of Solvated Semi-Interpenetrating Polymer Network Silicone Hydrogels
… attempting to understand their constitutive and fracture properties in order to improve hydrogel manufacturing and performance in applications. In this thesis, a series of experimental techniques were developed or adapted from common engineering approaches in order to investigate the effects of …
-
Effects of moisture on debonding in FRP-retrofitted concrete systems
… moisture conditioning, using the concept of fracture mechanics and meso-scale tri-layer fracture specimens. Prolonged exposure to moisture condition has been shown to result in significant degradation of the FRP/concrete bond strength, while an irreversible weakening in the bond strength has …
-
Demolding of hot embossed polymer microstructures
… work--has been proposed by analogy with interfacial fracture and has been related to underlying physical mechanisms. Finite element simulations based on this theory of demolding have been performed to investigate the effects of important parameters, including demolding temperature and …
-
Delamination in reinforced concrete retrofitted with fiber reinforced plastics
… tip. For this reason it is shown that interfacial fracture mechanics can be used to describe the bimaterial elasticity and complex stress intensity at the delamination tip and provide a criterion governing the propagation of delamination using energy methods. Then, peeling processes …
Page 1 of 2