Date of Award

8-2018

Degree Type

Report

Degree Name

Master of Science (MS)

Department

Mechanical and Aerospace Engineering

First Advisor

Thomas H. Fronk

Second Advisor

Steven R. Folkman

Third Advisor

Robert E. Spall

Abstract

Composite I-beams are popular for high-strength low-weight applications. Learning the macro-mechanics and designing the composite I-beam properly are necessary. In this report, a design overview of the composite I-beam is discussed which is based on classical lamination theory where it includes the homogenization approach, the plane stress assumption and the Kirchhoff hypothesis. Using these assumptions, a method was developed to come up with the effective material properties of a beam. Formulas to calculate maximum deflection and maximum bending stress and shear stress and the stress concentration at the connection of web-flange are discussed which describe ways for designing and manufacturing the I-beam.

Ideas for manufacturing I-beams are based on unidirectional fibers. Critical design considerations are discussed. The design considerations for stacking sequences, cross section, length of the beam, failure, buckling are discussed to give an insight to achieve intended I-beam design goals more effectively. For stacking sequences, it is found that the sequencing of the layers depends on configuration and loads applied on the beam. To counter shear, 45° layers are needed and to counter tension and compression, cross-ply are iv best. Minimizing cross-section while having more web height compared to flange width will strengthen the beam. Finally, some recommendations are made for future directions from this project.

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