1,722,409 research outputs found
1961 -- Correspondence, Unsorted -- letter, 1961-07-26
No full textLetter from Zacek, Karel to Sabin, Albert B. dated 1961-07-26.Sabin Collection Fair Use Policy</a
Czechoslovakia -- 1958-60 -- Correspondence, OPV International -- letter, 1959-04-25
No full textLetter from Zacek, Karel to Sabin, Albert B. dated 1959-04-25.Sabin Collection Fair Use Policy</a
Czechoslovakia -- 1958-60 -- Correspondence, OPV International -- letter, 1958-09-30
No full textLetter from Zacek, Karel to Sabin, Albert B. dated 1958-09-30.Sabin Collection Fair Use Policy</a
1959, Jan.-Aug. -- Correspondence, Unsorted -- letter, 1959-06-26
No full textLetter from Zacek to Sabin, Albert B. dated 1959-06-26.Sabin Collection Fair Use Policy</a
Czechoslovakia -- 1958-60 -- Correspondence, OPV International -- letter, 1958-11-25
No full textLetter from Zacek, Karel to Sabin, Albert B. dated 1958-11-25.Sabin Collection Fair Use Policy</a
Joseph Frederick Zacek, Palacky. The Historian as Scholar and Nationalist
No full textMichel Bernard. Joseph Frederick Zacek, Palacky. The Historian as Scholar and Nationalist. In: Annales. Économies, Sociétés, Civilisations. 29ᵉ année, N. 2, 1974. pp. 446-447
Exploring the link between microstructure statistics and transverse ply fracture in carbon/epoxy composites
Get PDFDamage evolution within polymer matrix composites (PMCs) is difficult to characterize, as variability arises in the material microstructure from manufacturing and in the local strength of the constituents, which is inherently statistical. Transverse failure of unidirectional plies is particularly critical in composite laminates, as it is often a precursor for other, more catastrophic failure modes such as delamination and fiber breakage. Although it is possible to attempt to orient fibers primarily in the directional of external loads, avoiding transverse stress concentrations is unattainable, and this will often lead to failure within the ply. The possible interaction of failure mechanisms makes obtaining reliable strength predictions under general loading difficult. This project is dedicated to understanding how the underlying statistics affect the failure of unidirectional composites, and to develop tools to analyze real unidirectional composite microstructures.
The first part of this study is focused on reconstructing micrographs of experimental composites and looking at various statistical metrics. We create a computational tool for predicting initial debonding sites based on geometry alone. From there, we create “virtual” microstructures that mimic some of the statistics that describe the real microstructure. We then perform some mesoscale simulations that focus on the cohesive failure of the interfaces between the fibers and the surrounding matrix material. Finally, an analytical material sensitivity formulation is derived and implemented using the direct differentiation method implemented in a C++ Interface-enriched Generalized Finite Element Method (IGFEM) framework. Emphasis is placed on extracting the sensitivity of the transverse failure response with respect to the two material parameters that characterize the interfacial cohesive failure: a critical stress (σ_c) and a critical opening displacement (δ_c).Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2017-08-10 without embargo termsThe student, Scott Zacek, accepted the attached license on 2017-01-18 at 11:19.The student, Scott Zacek, submitted this Thesis for approval on 2017-01-18 at 11:24.This Thesis was approved for publication on 2017-01-19 at 17:27.DSpace SAF Submission Ingestion Package generated from Vireo submission #10541 on 2017-08-10 at 13:37:24Made available in DSpace on 2017-08-10T19:14:25Z (GMT). No. of bitstreams: 2
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Previous issue date: 2017-01-1
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