Norman M. Wereley - US grants

The objective of this integrated education and research plan is to augment damping in large civil structures applications, via both passive and active means, to reduce structural response. The proposed research program will develop, analyze and experimentally demonstrate passive, semi-active, and active structural damping control for civil structures using smart materials and structures technology. The research builds on the ongoing research efforts at Maryland on stability augmentation, shock, and vibration control using electrorheological (ER) and magnetorheological (MR) dampers. Damping strategies will be tested on dynamically scaled three story civil structures building model currently under development.

Walking for a healthy adult seems easy. However, underlying this apparent simplicity our nervous system is performing a task of astounding complexity. Using sensory information about body movement, the nervous system coordinates the activation of dozens of muscles so that we stably and efficiently move through our environment. For example, if our nervous system senses that our foot will strike the ground too soon, it will adjust muscle activations so we do not stumble and fall. In this project, an interdisciplinary team of investigators aims to uncover the rules the nervous system uses to make such adjustments. Using a general theoretical framework taken from engineering (used to understand, for example, the rhythmic control of the angle of attack of rotating helicopter blades), the method depends on gently perturbing a person's senses and body in various ways and observing how the nervous system adjusts muscle activations in response. The investigators will first test their methods on a simpler type of rhythmic movement, repetitive hitting of a virtual ball with a paddle, then extend the findings to coordination during walking.

By constructing a general approach to understanding the control of rhythmic movements, including swimming in fish, flying in insects and birds, and walking in people and robots, the investigators may provide a foundation for understanding how control breaks down for people with neurological conditions such as stroke and incomplete spinal cord injury. This has the potential to advance neuromuscular rehabilitation and the design of assistive devices.

[Co-funded by CISE and SBE]

Researchers are working on a technology for 24/7 detection of bridge scour. The system leverages advances in sensor technologies to provide cost-effective early detection of bridge scour and the means to avoid bridge failure and associated costs. The scour sensing technology uses magnetostrictive flow sensors that are buried in the soil around bridge foundations. As scour develops and the soil begins to erode, the sensors are activated and able to detect water flow and automatically alert the bridge owner that remediation is needed. The macroscale and nanoscale magnetostrictive fluidic sensors investigated with prior NSF support are the basis for the advanced flow sensors system that is being used to provide robust and continuous detection of bridge scour.

Scour monitoring is a federally mandated part of regular bridge inspections but often bridge owners do not have sufficient manpower to inspect their entire bridge inventories more than once every year or two. Scour can thus go undetected for long periods of time and develop into very costly and even life threatening problems. The candidate scour detection system could both improve public safety and save costs to the owners of bridges. This is because the early scour detection can significantly reduce repair costs, which in cases of advanced scour, can involve the cost of a complete bridge replacement. A bridge experiencing or at risk of even moderate scour may be closed resulting in a significant economic impact on the surrounding communities. Often the solution to moderate to severe scour is replacement of an otherwise sound bridge at a significant cost. Early scour can be repaired at a cost of a few thousand dollars but late stage scour can cost a few hundred thousand to repair or millions if the bridge needs to be replaced.