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Showing 1 to 14 of 14 for “"Critical Strain Energy Release Rate"”.
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Investigation of the Effects of Geometry on the Efficiency of the Double Lap Joint of Unidirectional Fiberglass Composites
… resistance at instability and the corresponding critical strain energy release rate are independent of initial crack length in the range of crack length investigated. The critical strain energy release rate in Mode II is roughly six times higher for the elliptical geometry than for the …
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Time- and Temperature-Dependence of Fracture Energies Attributed to Copper/Epoxy Bonds
… to related, high-speed failure events. Work (or energy) is required to create new surface area—with associated dissipation events—during fracture, and this energy (for a given material system) is dependent on the speed of crack propagation, the locus of failure, and the temperature of the bond …
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An Evaluation of the Durability of Polymer Concrete Bonds to Aluminum Bridge Decks
… times varied from none to twelve months. The critical strain energy release rate (Gc) of the bond was determined using a compliance technique. In spite of considerable scatter in the data, the results suggested that the interfacial bond toughness had been degraded by exposure conditions. The …
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Interface durability of externally bonded GFRP to normal and high-performance concrete
… interface is characterized based on the critical strain energy release rate, under Mode-I loading, and weight and strain measurements. Unconditioned companion specimens are fractured alongside their aged counterparts to provide baseline-feedback and also enable comparative analysis of the …
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Environmental Influence on the Bond Between a Polymer Concrete Overlay and an Aluminum Substrate
… a polymer concrete overlay and an aluminum substrate. The purpose of this investigation is to evaluate the bond durability between the overlay and the aluminum substrate after conditioning specimens in various temperature and humidity conditions. The average critical strain energy release rate, …
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The notched coating adhesion specimen: a fracture test for coatings and accelerated screening test for adhesion
… adhesion (NCA) specimens consist of single substrates coated with thin layers of adhesive. The coating is notched to induce initial debonds, and the specimen is then loaded in a manner to produce tensile stresses in the coating. The substrate strain at which the coating debond propagates is then …
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Improvement in Adhesion for the Epoxy-SiC System via Plasma and Silane Surface Modification Techniques
… the adhesion between an adhesive and its substrate is typically compromised. This thesis addresses the advantages of employing plasma pretreatments and surface derivatization using silane coupling agents as surface modification techniques in an effort to enhance the adhesive bonding of epoxy to …
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Strain-rate Dependent Fracture Load Prediction of Lead-free Solder Joints
The critical strain energy release rate at crack initiation, Jci, has been shown to govern the fracture of short solder joints. The present work measured Jci for 2 mm long SAC305 solder joints as a function of the strain rate and phase angle using DCB specimens. A drop tester was designed and built …
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The effect of sintering and CMAS on the stability of plasma-sprayed zirconia thermal barrier coatings
… thermal expansion coefficient and high in-plane strain tolerance. However, as turbine entry temperatures are raised, the performance of 7YSZ coatings will be increasingly affected by sintering and environmental contamination, by calcia-magnesia-alumina-silica (CMAS) deposits. The effect of …
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Quantitative evaluation of thin film adhesion using the probe test
… of a thin polymeric coating bonded to a substrate, causing the edge to lift-up from the surface of the substrate. A debond is thus initiated at the loading point and propagates as a semi-circular crack at the interface as the probe slides under the coating. A standard test procedure has been …
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Analysis of Bimetallic Adhesion and Interfacial Toughness of Kinetic Metallization Coatings
… without compromising the properties of the substrate, coatings have become ubiquitous in heavy industrial applications for corrosion, wear, and thermal protection, among others. Kinetic Metallization (KM), a solid-state impact consolidation and coating process, is well-suited for depositing …
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Mechanical Characterization of Coating-Interconnect Interfaces and Anode-Electrolyte Interfaces for Solid Oxide Fuel Cells
… units in a planar SOFC stack are physically separated by electrically conductive interconnects. With the reduction of operating temperature to 800oC, it is possible to replace lanthanum based ceramics with less expensive, more readily available chromium alloyed iron metals as interconnects. …
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Characterization of Mechanical Properties at the Micro/Nano Scale: Stiction Failure of MEMS, High-Frequency Michelson Interferometry and Carbon NanoFibers
… and experimentally. Specifically, the adhesion energy of poly-Si μcantilevers are determined experimentally through Mode II and mixed Mode I&II crack propagation experiments. Furthermore, the description of a high-frequency Michelson Interferometer is discussed for imaging of crack propagation …
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Assessment of Fracture Resistance of Asphalt Overlays through Heavy Vehicle Simulator and Laboratory Testing: Synthetic Fiber and Rubber Modified SMA Mixes
… agencies often opt for overlaying the deteriorated PCC pavement with Hot Mix Asphalt (HMA), resulting in a composite pavement. Unfortunately, the tensile stresses and strains at the bottom of the overlay developed from the movement of the joints, which are caused by the traffic and the changes …