Mechanical Engineering Commons^™

Energy Dissipation In A Sand Damper Under Cyclic Loading, Ehab Sabi

Civil and Environmental Engineering Theses and Dissertations

Various seismic and wind engineering designs and retrofit strategies have been in development to meet structures' proper and safe operation during earthquake and wind excitation. One such method is the addition of fluid and particle dampers, such as sand dampers, in an effort to reduce excessive and dangerous displacements of structures. The present study implements the discrete element method (DEM) to assess the performance of a pressurized sand damper (PSD) and characterize the dissipated energy under cyclic loading. The idea of a PSD is to exploit the increase in shearing resistance of sand under external pressure and the associated ability …

Damage Evolution And High-Rate Response Of High-Strength Concrete Under Triaxial Loading, Brett Williams

Mechanical Engineering Research Theses and Dissertations

The research presented in this study focuses on understanding fundamental mechanisms that drive material response under dynamic loading conditions. The objectives of the research were to: (1) to understand damage initiation and propagation in the bulk geomaterial under a variety of loading conditions and (2) to systematically investigate the strain rate effects on the triaxial compressive response of cementitious materials through the development of an innovative, first of its kind large-diameter (50 mm) triaxial Kolsky bar system.

The triaxial compressive response of high-strength concrete is needed to understand pressure-dependent material behavior, which is important for modeling extreme loading events. However, …

Design Of A Greywater-Fed Hydroponics System, Alex Estrada, Katya Fairchok, Andrew Feldmeth, Andrew Jezak

Interdisciplinary Design Senior Theses

To combat issues of local water insecurity, a hydroponics system was designed in partnership with LEAP 5 High School in Jane Furse, South Africa. Climate change, increasing human population, and continued environmental degradation all threaten access to clean drinking water. Approximately seventy percent of all freshwater is used for agriculture globally, thus threatening food security especially in developing countries where access to water is potentially volatile. The hydroponics garden system utilizes sustainable materials, a self-monitoring temperature controls system, and greywater input, to act as an educational tool for students and significantly reduce freshwater use compared to traditional, in-ground agriculture. An …