Mechanical property degradation due to isothermal ageing is of potential concern for alloys based on the Ni-Cr binary system (e.g., Inconel 690, 625), particularly in nuclear power applications where component lifetimes can exceed 40 years. In the present research, the disorder-order phase transformation, which is the primary mechanism of ageing,...
Concrete is the most widely used construction material in the world. When constructing large concrete structures, concrete may have to be placed in multiple lifts. In these cases, fresh concrete is placed on hardened concrete. The interface that is formed between these two lifts of concrete is known as a...
Bipedal locomotion is a complex phenomenon to understand and control, making it difficult for legged robots to achieve the speed, agility, efficiency, and robustness of their animal counterparts. This thesis argues for the use of numerical optimization to investigate and implement bipedal control as it applies to biology, dynamical models,...
In the field of civil infrastructure, bridge desks are typically constructed using high performance concrete (HPC). Concrete bridge decks demand qualities such as low permeability, high abrasion resistance, superior durability, and long design life. Over decades of field and laboratory experience, many HPC bridge decks have been found to be...
Information reviewed and reaffirmed, 1962. Original report published in 1946. This report is one of a series issued in Cooperation with the Army-Navy-Civil Committee on Aircraft Design Criteria under the supervision of the Aeronautical Board.
The goal of this project is to contribute to the development of design values for cross-laminated timber (CLT) diaphragms in the seismic load-resisting system for buildings. Monotonic and cyclic tests to determine strength and stiffness characteristics of 2.44 m (8 ft) long shear connections with common self-tapping screws were performed....
Duplex stainless steels (DSS) are an attractive potential material in nuclear power generation systems due to an excellent combination of corrosion resistance, strength, toughness, and affordability. Thermal embrittlement caused by phase instability in the temperature range of ~300-550°C severely limits the service temperature of DSS. The rate of embrittlement varies...
As people learn new concepts, they experience a process termed conceptual change. There are several theories that attempt to explain conceptual change, and this paper uses the framework theory to explain how students learn mechanics of materials. Semi-structured interviews with ninety students were qualitatively analyzed for this research in an...