The objective was to develop and characterize a potential method to alleviate the issues regarding post impact effective modulus of composites in a tubular geometry. The hypothesis was that the use of a metallic substrate may increase post impact stiffness characteristics of the sample geometry, compared to a traditional fiber reinforced composite tube, in the torsion and tensile loading scenarios. This required the manufacture of non substrate fiber reinforced composite samples and aluminum substrate composite samples, and testing under torsion and tension loading scenarios. Main sample testing was carried out below the sample yield point, and therefore tests were nondestructive in nature.
This research has concluded with statistical significance that an aluminum substrate decreases loss in torsional effective modulus following impact compared to a composite shaft only composed of carbon fiber reinforced epoxy. Samples with both aluminum sleeve factor levels produced significantly lower post impact effective modulus change compared to traditional composite counterparts. This appears to be correlated with the elimination of visible fiber and matrix rupture during the impact event. Therefore, torsional effective modulus decrease of the aluminum sleeve tubes appears to be dictated by tube geometry change. This is in contrast to traditional composite tubes, where a decrease in effective modulus was primarily dictated by the decrease in fiber cross sectional area.
This research has concluded that the aluminum substrate decreases post impact tensile effective modulus change compared to traditional composite tubes, but statistical significance could not be attained due to the high degree of variance within each of the sleeve thickness factor levels. Samples with aluminum sleeves produced lower post impact effective modulus change compared to the traditional composite counterparts, but each sample sleeve thickness factor level variance was relatively high compared to the difference in mean values.
Manufacturing and Mechanical Systems Integration (MS)
Department, Program, or Center
Manufacturing and Mechanical Engineering Technology (CAST)
Eastwood, Charles R., "The Influence of a Metallic Substrate on the Post Impact Structural Characteristics of a Composite Shaft" (2017). Thesis. Rochester Institute of Technology. Accessed from
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