Engineering

In this thesis, we will explore different kinds of metamaterial or architectural structural problems, including structures composed of heterogeneous media with bi periodic sub-structures, discrete structures with sub-elements or continuous structures with discrete attached sub-elements. The thesis is composed of seven parts. After having introduced the specificities of metamaterial mechanics, the second chapter is devoted to the vibration of discrete beam problems called Hencky bar-chain model in a stochastic framework. It is shown that the lattice beam behaves as a nonlocal continuous beam problem, both in the deterministic and the non-deterministic analyses. The third chapter considers the vibration of continuous beams with the introduction of shear effects and attached periodically oscillators. A discussion on beam modelling, for example Timoshenko beam models or truncated Timoshenko beam models is included. It is shown that the bandgap phenomenon observed for metamaterial beams can be accurately captured by a truncated Timoshenko beam model which means the last term in the Timoshenko equation is not that important.

The purpose of this study was to identify factors that are associated with encourage the persistence of undergraduate women majoring in Engineering and Math (EM) at Florida Atlantic University, University of Central Florida, and University of South Florida. The persistence factors were examined through an analysis of university data and the use of a survey for enrolled senior standing students who declared their first major in engineering or math. Both quantitative and qualitative methods were utilized to collect and analyze data from the three sites. Factor analysis and logistic regression were used to analyze the quantitative data. The quantitative data retrieved from the survey instrument revealed that participants who were self motivated, felt they had a safe learning environment, and were engaged by the university were more likely to persist in engineering and math. Additionally, the survey revealed that race and ethnicity does not predict persistence of undergraduate women maj oring in engineering and math. Qualitative analysis of open-ended survey questions revealed that the most important factor that helps female students persist in engineering and math major was self-confidence and determination. They also indicated that discrimination and stereotyping were the most difficult factors for female students to overcome. To enable more women to be successful in the pursuit of a engineering or math degree, participants made an overwhelming reference to intervention as student engagement.