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Stiffness and Failure Behavior of Model Hybrid Composites



Donald L. Hunston, Walter G. McDonough


Many applications are exploring the use of hybrid composites; i.e., polymers reinforced with two different types of fibers, because such systems can have a superior balance of properties and/or a better balance of properties and cost. Unfortunately, the behavior of hybrid is not adequately modeled with current theories. This paper examines the properties of a simple model hybrid made by combining one to four individual tows of glass and carbon into unidirectional samples. To determine the role of the resin, samples were made with and without resin. The experiments on single fibers showed that they behave as expected so failure can be descried with Weibull statistics. For tests on individual and hybrid tows, the measured stiffnesses generally fit with predictions from the moduli of the individual fibers using a rule of mixtures model. The failure behavior of tows with no resin is a cumulative process in which the fibers seem to behave independently so the results can be modeled fairly well from knowledge of the fiber mix and the failure behavior of the individual fibers. When resin is present, the failure behavior shifts to catastrophic although samples containing significant glass exhibit some gradual failure before complete fracture. The hybrid samples were found to show a so-called hybrid effect in that the strength was higher than would be expected based on simple failure models.
American Society for Composites. Technical Conference


carbon, failure, fiber, glass, hybrid, stiffness, strength


Hunston, D. and McDonough, W. (2002), Stiffness and Failure Behavior of Model Hybrid Composites, American Society for Composites. Technical Conference, [online], (Accessed July 18, 2024)


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Created October 21, 2002, Updated February 19, 2017