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- Creators: Mechanical and Aerospace Engineering Program
- Creators: El Asmar, Mounir
- Status: Published
The goal of this experiment was to examine the energy absorption properties of origami-inspired honeycomb and standard honeycomb structures. These structures were 3D printed with two different materials: thermoplastic polyurethane (TPU) and acrylonitrile butadiene styrene (ABS). Quasi-static compression testing was performed on these structures for both types and materials at various wall thicknesses. The energy absorption and other material properties were analyzed for each structure. Overall, the results indicate that origami-inspired structures perform best at energy absorption at a higher wall thickness with a rigid material. The results also indicated that standard honeycomb structures perform better with lower wall thickness, and also perform better with a rigid, rather than a flexible material. Additionally, it was observed that a flexible material, like TPU, better demonstrates the folding and recovery properties of origami-inspired structures. The results of this experiment have applications wherever honeycomb structures are used, mostly on aircraft and spacecraft. In vehicles with structures of a sufficiently high wall thickness with a rigid material, origami-inspired honeycomb structures could be used instead of current honeycomb structures in order to better protect the passengers or payload through improved energy absorption.
The built environment is responsible for a significant portion of global waste generation.
Construction and demolition (C&D) waste requires significant landfill areas and costs
billions of dollars. New business models that reduce this waste may prove to be financially
beneficial and generally more sustainable. One such model is referred to as the “Circular
Economy” (CE), which promotes the efficient use of materials to minimize waste
generation and raw material consumption. CE is achieved by maximizing the life of
materials and components and by reclaiming the typically wasted value at the end of their
life. This thesis identifies the potential opportunities for using CE in the built environment.
It first calculates the magnitude of C&D waste and its main streams, highlights the top
C&D materials based on weight and value using data from various regions, identifies the
top C&D materials’ current recycling and reuse rates, and finally estimates a potential
financial benefit of $3.7 billion from redirecting C&D waste using the CE concept in the
United States.
The author hypothesized that there are specific practices that, if properly implemented, can lead to instantaneous controls of capital projects. It is also hypothesized that instantaneous project controls pose benefits to project performance. This research aims to find practices and identify benefits and barriers to achieving a real-time mode of control. To achieve these objectives, several lines of inquiry had to be pursued. A panel of 13 industry professionals and three academics collaborated on this research project. Two surveys were completed to map the current state of project control practices and to identify state-of-the-art or ideal processes. Ten case studies were conducted within and outside of the capital projects industry to identify practices for achieving real-time project controls. Also, statistical analyses were completed on retrospective data for completed capital projects in order to quantify the benefits of IPC. In conclusion, this research presents a framework for implementing IPC across the capital projects industry. The ultimate output from this research is procedures and recommendations that improve project controls processes.