Off-campus UMass Amherst users: To download campus access theses, please use the following link to log into our proxy server with your UMass Amherst user name and password.
Non-UMass Amherst users: Please talk to your librarian about requesting this thesis through interlibrary loan.
Theses that have an embargo placed on them will not be available to anyone until the embargo expires.
Access Type
Open Access
Document Type
thesis
Degree Program
Mechanical Engineering
Degree Type
Master of Science in Mechanical Engineering (M.S.M.E.)
Year Degree Awarded
2012
Month Degree Awarded
September
Keywords
Cebus apella, finite element analysis, probabilistic design, material stiffness orientation, cranial structure morphology, maximum principal strain orientation
Abstract
Probabilistic finite element analysis was used to determine whether there is a statistically significant relationship between maximum principal strain orientations and orthotropic material stiffness orientations in a primate cranium during mastication. We first sought to validate our cranium finite element model by sampling in-vivo strain and in-vivo muscle activation data during specimen mastication. A comparison of in vivo and finite element predicted (i.e. in silico) strains was performed to establish the realism of the FEM model. To the best of our knowledge, this thesis presents the world’s only complete in-vivo coupled with in-vitro validation data set of a primate cranium FEM. Our results indicate that a validated FEM of a Cebus apella cranium was achieved. Giving collaborating anthropologists, biologists, and engineers the confidence that these models have sufficient accuracy to address the research questions pertaining to cranial structure morphology.
Probabilistic finite element analysis design was then utilized to determine the dependence of maximum principal strain orientations on material stiffness orientations in particular craniofacial regions during mastication. It was discovered that the maximum principal strain orientations are more dependent on loading conditions and/or the shape of and location in the cranium rather than the material stiffness orientation of a particular region. It was also uncovered that the material stiffness orientations are not developed in a way that is optimal for feeding biomechanics from the perspective of minimization of total elastic strain energy. Results from this research will provide insights into the co-evolution of bone morphology and material properties in the facial skeleton.
DOI
https://doi.org/10.7275/3259472
First Advisor
Ian R. Grosse
Second Advisor
Robert Hyers