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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 55 for “"mode-I fracture"”.
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Mode I Fracture Testing on Zirconium Foils Under Plane-stress Condition
… to ensure such Zr components operate safely, fracture analysis of Zr alloys has been widely studied. Considering the high cost and difficulties associated with using neutron-irradiated Zr specimens for fracture analysis, proton irradiated testing has been proposed to reduce the cost and …
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Mode I Fracture Toughness Testing of Friction Stir Processed HSLA-65
… stir welding for use in Naval construction, mode one elastic-plastic fracture toughness of friction stir processed HSLA-65 was determined using current ASTM 1820 and BS 7448 standards. Double-sided welds were used to achieve 12.7 mm thick samples. A constant feed rate of 100 mm/min was used …
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Durability and mode-I fracture of fiber-reinforced plastic (FRP)/wood interface bond
… program to evaluate the service performance and fracture of composite/wood bonded interfaces. The proposed method is used for two types of FRP wood interface: FRP strips (plates) bonded to wood (used commercially for glulam timber beams) and wood cores wrapped with FRP by filament winding (being …
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Synthesis, characterization, and mode I fracture toughness of aligned carbon nanotube polymer matrix nanocomposites
… composites, particularly steady state Mode I fracture toughness, RTM6 and EPON 862/W epoxy based vertically-aligned carbon nanotube (A-CNT) polymer nanocomposites (A-PNCs) are manufactured. These A-PNCs can be tested to isolate structure-property relationships between the polymer matrix …
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Mechanical enhancement of woven composites with radially aligned carbon nanotubes (CNTs) : investigation of Mode I fracture toughness
… increased complexity and challenging failure modes. Matrix-rich regions at ply interfaces especially are susceptible to damage and matrix cracking, leading to delamination and a reduction of mechanical properties. Several manufacturing solutions such as stitching, z-pinning, and braiding have …
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Experimental Characterization of Mode I Fracture Toughness of Reinforced Carbon Fiber Laminate with Nano-Cellulose and CNT Additives
Effective treatment of carbon fiber components to improve delamination resistance is vital to the application of such materials since delamination is one of the biggest concerns regarding the use of composites in the aerospace sector. Due to the significant application benefit gained from increased …
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Mode-I Fracture in Bonded Wood: Studies of Adhesive Thermal Stability, and of the Effects of Wood Surface Deactivation
… studies; the common theme in each was the use of mode-I fracture testing to evaluate wood adhesion. In the first study, mode-I fracture testing was used to compare the thermal stability of polyurethane (PUR) and resorcinol-formaldehyde (RF) wood adhesives. Bonded specimens for both adhesives were …
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Experimentation of Mode I and Mode II Fracture of Uni-Directional Composites and Finite Element Analysis of Mode I Fracture Using Cohesive Contact
… One of the most prevalent and limiting mode of failure within composite laminates is delamination, since it not only reduces a structures stiffness and strength, but can be very difficult to detect without the use of special non-destructive equipment. Industry testing organizations have …
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Fracture mechanics and its application in rock excavation
… two chevron notched specimen geometries for rock Mode I fracture toughness measurement, CB and SR, recommended by the ISRM have several disadvantages, such as very low loads required to initiate failure, complicated loading fixtures, difficult to be developed for rock mixed mode fracture testing, …
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Species Dependence of pMDI/Wood Adhesion
… The present is divided into two parts. First, mode I fracture mechanics and surface free energy analysis was performed to investigate differences in adhesion between southern yellow pine and yellow-poplar bonded with pMDI. Secondly, an improvement in the synthesis of 13C, 15N labeled pMDI is …
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Rheometric measurement of hydrogel toughness
… We present a novel method for measuring fracture energy using a rheometer and show it is broadly consistent with the pure shear test, a standard method where the material exhibits mode I fracture. This method has potential applications in characterizing a wide range of soft and transient …
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Cohesive zone modeling of fracture of sustainable and functionally graded concrete
… other design requirements such as ductility, fracture resistance, thermal resistance/insulation, etc. Functionally graded materials (FGMs) are one such material. This study investigates the fracture process of sustainable concrete, fiber reinforced concrete, and of functionally graded concrete …
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Fracture characterization of clays and clay-like materials using flattened Brazilian Test
Fracture mechanics has been used for many years to study the mechanical behavior of brittle and quasi-brittle materials like concrete, rock, wood, and ceramics. To date, the application of fracture mechanics to soils has been limited to dry and partially saturated soils where soil consistency …
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Exploration of Wood DCB Specimens Using Southern Yellow Pine for Monotonic and Cyclic Loading
… beam (DCB) as a valid means for testing Mode I fracture energy in wood adhesive bonds. Southern yellow pine (SYP) adherends were used with epoxy and phenol formaldehyde (PF) impregnated films, providing two systems with different characteristics for investigation. An adhesive penetration …
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The Comparison of Composite Aircraft Field Repair Method (CAFRM) with Traditional Aircraft Repair Technologies
… acid digestion, short beam shear, and mode I fracture tests. The researcher was able to determine the specimen's void content, fiber volume fraction, shear strength, and opening mode interlaminar fracture toughness for the specimens fabricated using the different repair methods. The …
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Mode I Delamination Fracture Characterization of Polymeric Composites under Elevated Temperature
<p>Delamination is one of the major failure modes seen in the laminated polymeric matrix composite (PMC). Accurate prediction of delamination initiation and propagation is important for the design and analysis of robust composite structures. Existing experimental methodologies that are based on …
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Carboxymethylcellulose Acetate Butyrate Water-Dispersions as Renewable Wood Adhesives
… analysis, light and fluorescence microscopy, and mode I fracture testing. Thermal analyses showed that the polymer glass transition temperature significantly increased when bonded to wood. CMCAB dispersions produced fairly brittle adhesive-joints; however, it is believed toughness can likely be …
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Development of aromatic polyesters for high performance applications and use of interchain transesterification reactions as a solid-state fabrication tool
… during retrace experiments. As well, the wear mode of amorphous ATSP coatings maintains this performance at applied loads significantly in excess of any other observed coating. It is hypothesized that the crosslinked structure and potential for the aromatic polyester chains to deform via …
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Fracture of Asphalt Concrete: A Cohesive Zone Modeling Approach Considering Viscoelastic Effects
… that exhibits time and temperature dependent fracture behavior. Softening of the material can be associated to interlocking and sliding between aggregates, while the asphalt mastic displays cohesion and viscoelastic properties. To properly account for both progressive softening and …
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