Jets in crossflow are used in a wide range of engineering applications and have been studied for more than 60 years. The transversal penetration and structure of a jet placed in a crossflow is known to be strongly three-dimensional. It is believed that, by using a pulsed jet inclined in...
Tensegrity structures are composed of pure compressional elements that are connected via a network of pure tensional elements. The concept of tensegrity promises numerous advantages to the field of robotics. Tensegrity robots are, however, notoriously difficult to control due to their oscillatory nature and nonlinear interaction between the components. Multiagent...
Nickel (Ni)-based alloys with a high chromium (Cr) content are frequently employed in applications where elevated temperatures and/or corrosive environments are present due to their excellent corrosion resistance and mechanical properties. However, a gap exists around the formation, and kinetics of long-range order (LRO) Ni2Cr phase in both model binary...
As robotic systems become increasingly prevalent in our lives (e.g., by harvesting food, assisting with disaster response and defense, and transporting persons and our goods around the world) there is a growing need to ensure that they can cooperate to achieve their intended goals. Robotic cooperation in the real-world is...
It is desirable for complex engineered systems to perform missions efficiently and economically, even when these missions' complex, variable, long-term operational profiles make it likely for hazards to arise. It is thus important to design these systems to be resilient so that they will actively prevent and recover from hazards...
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,...
The operation of gas turbine engines depends on the reliable ignition of fuel/air mixtures. Gas turbine engines are commonly used as commercial and military aviation power plants. However, consistent ignition within gas turbine engines is still a problem, especially for more challenging operating conditions such as emergency operations. This work...
A need exists to develop a non-destructive testing technique that can identify
the formation and propagation of diagonal tension cracks in conventionally
steel reinforced concrete deck girder (RCDG) highway bridges in the State of
Oregon. Such a technique could be included into a structural health
monitoring (SHM) system installed on...
Modern engineered systems are increasingly integrated into society, decentralized, and interconnected. However, scale and complexity create unique challenges in system design, such as emergent behavior and unintended consequences. This work investigates the structural characteristics of robustness in complex engineered systems by identifying patterns of under-recognized vulnerabilities at various levels of...
Clean technologies can address multiple challenges associated with climate change, environmental protection, and human health. However, the impact desired by introduction of such technologies is achievable only if new options effectively replace inefficient, conventional practices. This ‘design for adoption’ requires understanding of user motivations, associated beliefs, context of use, and...