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Document Type

Campus Access

Degree Program

Mechanical Engineering

Degree Type

Master of Science in Mechanical Engineering (M.S.M.E.)

Year Degree Awarded

2011

Month Degree Awarded

September

Keywords

Parametric CAD Modeling, Finite element analysis, Biological CAD modeling, Bat skull, morphology, morpho-design space

Abstract

In order to understand the relationship between feeding behavior and the evolution of mammalian skull form, it is essential to evaluate the impact of bite force over large regions of skull. There are about 1,100 bat species worldwide, which represent about 20% of all classified mammal species. Hence, a study in the evolution of bat skull form may provide general understanding of the overall evolution of skull form in mammals. These biomechanical studies are generally performed by first building solid Finite Element (FE) models of skull from micro CT scans. This process of building FE models from micro CT scans is both tedious and time consuming. Therefore a new approach is developed in this research project to build these FE models quickly and efficiently.

I have used SolidWorks to build a parameterized, three dimensional surface CAD model of a skull of the short-tailed fruit bat, Carollia perspicillata, by using coordinate data from an STL model of the species. The overall shape of this model closely resembled that of solid model of C. perspiciallata constructed from micro CT scans. Finite element analyses of the solid and surface models yielded comparable results in terms of magnitude and distribution of von Mises stress and mechanical advantage. Using this parametric surface model, the FE plate or shell element models of different bat species were generated by varying two parameters, palate length and palate width. Parametric analyses were performed on these FE plate models of skulls and response surfaces of performance criteria: von Mises stress, strain energy and mechanical advantage were generated by varying the input parameters. After generating response surfaces, species of bats from the morphologically diverse family of New World leaf-nosed bats (Family Phyllostomidae) were overlain on these response surfaces to determine which portions of the performance design space (palate length X width) are and are not occupied. These plots serve as a foundation for understanding the affect of different performance criteria on the evolution of bat skull form.

First Advisor

Ian R. Grosse

Second Advisor

Elizabeth R. Dumont

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