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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 14 of 14 for “"fiber pullout"”.
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Single Straight Steel Fiber Pullout Characterization in Ultra-High Performance Concrete
… to characterize single straight steel fiber pullout in Ultra-High Performance Concrete (UHPC). Several parameters were explored including the distance of fibers to the edge of specimen, distance between fibers, and fiber volume in the matrix. The pullout load versus slip curve was …
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Toughening mechanisms in weak matrix ceramic composites
… is closely related to the weak interface between fiber and matrix. The weak interfaces in composites have been provided by reducing the chemical bonding and the residual thermal stresses between constituents. A new way to introduce the weak interface by induced porosity or damaged zones, so called …
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Multiscale Computational Framework for Analysis and Design of Ultra-High Performance Concrete Structural Components and Systems
… law to account for the addition of discrete fibers. The approach is robust, general, and could be utilized by other researchers to expand the computational capability and simulate the behavior of different composite materials. The work described herein identifies the model material parameters …
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Low modulus, oxidation-resistant interface coatings for SiC/SiC composites
… composites failed gracefully, 1.e., there was fiber pullout and debonding probably at the matrix-coating interface. Minicomposites that contained tows coated using MOD were too weak to be tested for tensile strength. This necessitated the deposition of a thin (~ 30 nm) layer of carbon both on …
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Transverse fracture and fiber/matrix interface characteristics of hybrid ceramic matrix composites
… properties through the use of continuous fiber reinforcement; fine, randomly dispersed discontinuous fiber (or whisker) reinforcement; and a hybrid combination of both continuous and discontinuous fibers. This dissertation addresses two important aspects of determining and improving the …
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Tensile behavior of unidirectional and cross-ply ceramic matrix composites
… matrix composite (GCMC) reinforced with Nicalon fibers and a Blackglas™ composite also reinforced with Nicalon fibers. Both had a symmetric cross-ply layup. Initial observations of the composites showed significant porosity and some cracking in the Blackglas™ samples. The GCMC samples showed …
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Durability of Ceramic Matrix Composites at Elevated Temperatures: Experimental Studies and Predictive Modeling
… for unidirectional composites which incorporates fiber strength statistics, fiber degradation, and matrix damage was derived. The model is based on a micromechanical analysis of the stress state in a fiber near a matrix crack and includes the effects of fiber pullout and global load sharing from …
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Engineering properties of ring shaped polytheylene terephthalate (RPET) fiber self-compacting concrete
… used PET with straight or irregularly shaped fibers. It has been shown that PET has a weak interfacial bond with cement paste in the pullout load because of the lamellar shape of fibers. Therefore, ringshaped PET (RPET) fibers are introduced in this study to overcome the limitations of …
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Design and analysis of a composite wire-socket attachment
A detailed study of the feasibility of anchoring fiber reinforced plastic wires for civil engineering applications is presented. An experimental investigation using tensile testing machines is performed, testing anchorages of 1, 7 and 19 wires. Conventional strain gage and acoustic emission …
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Modeling of Strain-Hardening Cement-based Composites (SHCC)
… Thus, the addition of a small volume of short fibers is a well-known strategy to increase the ductility and toughness of cementitious matrices besides optimization of the crack opening. Strain-hardening cement-based composites (SHCCs) is a particular class of fiber-reinforced concretes (FRCC) …
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Development and Use of Moisture-Suction Relationships for Geosynthetic Clay Liners
… geotextiles reinforced with needlepunched fibers. A geofilm was adhesively bonded to the nonwoven side of one of the GCL products. The hydration solution tests involved hydrating GCLs with deionized water, tap water, 0.1 M CaCl<sub>2</sub>, or soil water from a landfill cover test plot for …
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Investigation of Machinability and Dust Emissions in Edge Trimming of Laminated Carbon Fiber Composites
The use of carbon fiber reinforced plastic (CFRP) systems for product structures has been steadily increasing because of superior material properties, including high strength, low weight, and corrosion resistance. CFRP parts may be molded to near net-shape geometry; however, machining operations …
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Manufacturing and fracture of hierarchical composite materials enhanced with aligned carbon nanotubes
… comprised of both nano- and micro-scale fibers are currently being studied as next-generation materials for multifunctional aerospace applications. Carbon nanotubes (CNTs) are an attractive reinforcing fiber for aerospace composites due to their scale and superior specific stiffness and …
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Structural Behaviour of Self Consolidating Steel Fiber Reinforced Concrete Beams
… stirrups are required. The use of steel fiber reinforced concrete (SFRC) could be considered as a potential alternative to the use of traditional shear reinforcement. Concrete is very weak and brittle in tension, SFRC transforms this behaviour and improves the diagonal tension capacity of …