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Showing 1 to 20 of 265 for “"ply"”.
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Compression failure of angle-ply laminates
… and mechanisms of failure in compression of angleply laminates. Experimental results were obtained from 42 angle-ply IM7/8551-7a specimens with a lay-up of [ (±9) / (=F9)] 6s where 9, the off-axis angle, ranged from 0° to 90°. The results showed four failure modes, these modes being a function of …
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A method for the ply-level elastic characterization of composite materials using thick tubular angle-ply specimens
… it is made. A method is presented by which the ply-level elastic properties of a composite material can be obtained for a common structure; a thick, laminated tube. The mechanical and thermal response of the tubes is modeled by a planar cylindrical elasticity solution. Properties are determined …
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Viscoelastic characterization of angle ply advanced composites
Time dependent properties of angle ply laminated Boron/Epoxy and Graphite/Epoxy fiber controlled composites were investigated. The main objective of this study was to develop a technique to establish interconversion of different test results using appropriate viscoelastic theory to formulate an …
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Delamination initiation in postbuckled dropped-ply laminates
The compression strength of dropped-ply, graphite-epoxy laminated plates for the delamination mode of failure is studied by analysis and corroborated with experiments. The nonlinear response of the test specimens is modeled by a geometrically nonlinear finite element analysis. The methodology for …
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Kinematics of Inter-Ply Interfaces In Composite Manufacturing
… during composite manufacturing. Strains, ply-movement, and formation of defects are observed in-situ using digital image correlation (DIC) during the autoclave cure cycle for the first time. The processing-induced defects in the composite are further characterized by X-ray micro-computed …
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Stresses and deformations in angle-ply composite tubes
… the stresses and deformations in angle-ply composite tubes subjected to axisymmetric thermal loading. For the theoretical portion, a generalized plane strain elasticity analysis was developed. The analysis included mechanical and thermal loading and temperature-dependent material …
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SMA-induced deformations in unsymmetric cross-ply laminates
… SMA-induced deformations in an unsymmetric cross ply laminate. A previously developed theory is used to predict the room-temperature shape of the cross-ply laminate by minimizing its total potential energy. Then, using the principle of virtual work, equations relating the shape of the laminate to …
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Finite element analysis of damaged cross-ply composite laminates
… cracks in T300/5208 graphite-epoxy cross-ply laminates was studied using generalized plane strain finite element analysis. The degradation of elastic modulus, Poisson's ratio, shear modulus, and coefficient of thermal expansion was predicted and then compared with analytical models and …
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Nonlinear Vibrations of Doubly Curved Cross-PLy Shallow Shells
… isotropic single-layered and multi-layered cross-ply doubly curved shallow shells with simply supported boundary conditions. The study is based-on the full nonlinear partial-differential equations of motion for shells. These equations of motion are based-on the von K\'{a}rm\'{a}n-type geometric …
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Tensile behavior of unidirectional and cross-ply ceramic matrix composites
… 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 considerably less damage. From the observed tensile behavior of the cross-ply composites, a 'back-out' …
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Investigation of Microcracking and Damage Propagation in Cross-Ply Composite Laminates
The present study investigates microcracking and damage progression in IM7/977-2, IM7/5555, and IM7/5276-1 [0/90/90/0] laminates. For each material system, seven to eight small coupons were axially loaded in a tensile substage. At increments of around 50 MPa the surfaces of the specimens were …
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Buckling and postbuckling behavior of laminated composite plates with ply dropoffs
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1986.
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Elastic and time dependent matrix cracking in cross-ply composite laminates
… time and stress level were investigated in cross-ply laminates to gain more understanding on the damage events in composites. Analytical predictions of the effect of stress level were performed for the case of linear elastic materials. The predictions were based on energy methods and linear …
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Tensile behavior of aluminum reinforced with angle-ply boron epoxy laminates
… behavior of aluminum reinforced with angle-ply boron/epoxy laminates was conducted. It is shown that the ultimate stresses of a wide variety of laminate configurations fall within a very narrow range of values. Some configurations of composite reinforced aluminum laminates exhibited higher …
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Local and Global Sensitivity Analysis of Thin Ply Laminated Carbon Composites
… orientation. Research has shown that decreasing ply thickness can reduce these interlaminar stress edge effects, and delay delamination in quasi-isotropic laminate specimen for laminates of equal total thickness. First ply failure stress has also been shown to increase with decreasing ply …
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Characterization of local strain fields in cross-ply composites under transverse loading
The student, Ariel Wilhelmsen, accepted the attached license on 2015-06-17 at 11:38.
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Effect of ply drop-offs on the strength of graphite-epoxy laminates
… were tested consisting of eight dropped-ply configurations, or values of N<sub>d</sub>. This geometry creates an eccentric load path which causes local bending moments in the region of the ply drop-off. The strength of a laminate with dropped-plies is less than the strength of its thin …
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Investigation of Surface Displacements Induced in Loaded Cross-Ply Composite Laminates with Microcracking
… models are created for eleven different cross-ply IM7/977-2 laminates with ply numbers varying from four to ten. Here, each ply thickness is 0.127mm, which is the common laminate thickness commercially available for this material system. For each model a range of transverse loadings are applied …
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Stresses and deformations in cross-ply composite tubes subjected to circumferential temperature gradients
The stresses and deformations in cross-ply composite tubes subjected in circumferential temperature gradients are studied. The motivation behind the study is the anticipated use of composite tubes in space structures where the tube is exposed to the heat of the sun on one side and the cryogenic …
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Thermally Induced Vibration of a Cross-Ply Laminated Plate with Hygrothermal Effects (Exact Solution)
… diffusion on one surface of a symmetric cross-ply plate made of AS/3501 graphite epoxy with simply-supported boundary conditions.</p>
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