The Mega-Structure Diagnostic and Prognostic System developed by The Hong Kong Polytechnic University (PolyU) has won the Special Prize and Gold Medal for its application in the Guangzhou New TV Tower at the 37th International Exhibition of Inventions, New Techniques and Products in Geneva in early April. This is yet another international recognition of PolyU's outstanding research achievements.

Being the landmark of the city, the Guangzhou New TV Tower will become the highest TV tower in the world with a total height of 610m, comprising a main tower of 454m and a 156m-high antenna. Designed with functions for sightseeing, TV transmission and cultural entertainment, the Tower comprises a Ferries wheel, observatory decks, ceremony hall, 4D cinemas, revolving restaurants, open-air skywalk, etc. To ensure safety during construction and operational performance during typhoons and earthquakes, an advanced monitoring system has been implemented for the first time in the supertall structure of the Tower by experts of the PolyU Department of Civil and Structural Engineering.

"The Mega-Structure Diagnostic and Prognostic System, making use of the fusion of technologies from different disciplines, such as sensing, communication, information technology, signal processing, data management, system identification, etc., provides structural monitoring, control, maintenance and management for mega-structures and performs a complete health monitoring throughout its life-cycle. The System does not only allow early identification of structural deterioration and damage for avoiding catastrophic structural failure, it also enables the assessment of structural safety immediately after unexpected disasters. The monitoring system can be applied to mega-structures like high-rise buildings and long-span bridges," said Dr. Yi-qing Ni, Principal Investigator of the monitoring system and Associate Professor of PolyU Department of Civil and Structural Engineering.

[PRLog]

SHM Articles

Here you can find an interesting collection of articles on SHM and NDT in general:

www.ndt.net

In particular, here is a list of articles on SHM.

Tobin Memorial Bridge Monitoring

In the next 18 months, the Massachusetts Port Authority’s (Massport) Tobin Memorial Bridge will be the state’s first bridge to have a wireless high-tech structural health monitoring system (SHM) in place to monitor stresses and strains in a real-time environment. In an effort to learn more about the behavior of the Tobin Bridge, Massport brought in an engineering consulting firm at a total project cost not to exceed $1 million. The firm will conduct structural modeling and analysis of forces and strains on the Tobin Bridge using a 3-D computer engineering model. Fay, Spofford & Thorndike (FST), located in Burlington, Mass., was chosen based on their overall qualifications and innovative approach. The firm’s knowledge base also is strengthened through an academic partnership with experts in the fields of structural engineering and computer analysis from Tufts University and the University of New Hampshire. A fourth member of the team, Geocomp of Boxborough, Mass., brings to the job worldwide expertise in placement and application of instrumentation. As a starting point, FST is working on the 3-D modeling, verification of results and recommendations for sensor and monitor placement on the Little Mystic truss and a six-span girder plate module on the Boston approach. These portions of the bridge were selected for their relatively simplified geometry in relation to the toll plaza and Big Mystic truss areas. A second phase for the Big Mystic truss also is under way. Further verification of the 3-D model results will be obtained by test loading of the Tobin Bridge once the sensors and monitors are installed. The test loading will consist of positioning fully loaded trucks along the bridge and recording the results. The test must be conducted when no other vehicle loading is on the portion of the span that is being tested. This will require that both decks of the Tobin Bridge be closed to traffic for a short period of time. The results of the test loading will help Massport engineers verify that the 3-D models are correctly predicting forces within the Tobin Bridge’s members and components. Once the verification process is complete, the models can then reliably be used to identify critical information points for sensor and monitor placement. These areas will include locations where elevated stress levels or unexpected deflections have been observed. At this writing, the initial 3-D models of the Tobin Bridge are still in development. Therefore, all key locations for sensor and monitor placement have not yet been finalized along with total project cost. [Roads and Bridges]

Dr. Bridge a new TV series on SHM

After the planetary success of Dr. House, another Princeton’s doctor is about to become the hero of a new TV series: Dr. Bridge.

BRIDGE, an innovative take on the structural drama, solves mysteries where the villain is a ill bridge and the hero is an irreverent, controversial doctor who trusts no one, least of all his patients.

Details on the new TV series can be found here.

U.S. Panel on Structural Control and Monitoring

An interesting intitiavie on SHM has an updated website.

The charter of the U.S. Panel on Structural Control and Monitoring is to accelerate the advancement of the science and practice of structural control and monitoring, by means of education, research and application of knowledge. This includes the response of large-scale structures to earthquakes, wind and man-made forces.  The U.S. Panel promotes and organizes activities including workshops, conferences and educational initiatives with the aim of fostering close collaboration between the academic and industrial communities.  In particular, the U.S. Panel has a proud tradition of assisting in the planning and execution of the International Workshop on Structural Control and Monitoring and the World Conference on Structural Control and Monitoring.

The website ca be found here: http://shm.engin.umich.edu/USPanel/index.html 

The Executive committe is chaired by prof. Shirley Dyke (Washington University) and prof. Jerome Lynch (University of Michigan, secretary). 

It contains useful information about SHM , conferences and test reports.

Using wireless sensors to monitor bridge safety

University of Texas (UT) professor, Dean Neikirk, will be field-testing a new bridge monitoring system within the year. The project is a collaboration between industry, government, and academia that will provide real-time monitoring of dangerous bridges and reduce inspection costs for all bridges.

"Most bridges have already been built," says Neikirk. "Our project will develop simple, low-cost equipment that can be used to retrofit existing construction as well as in new construction, but we are primarily concerned with ensuring that bridges do not fail without warning. Most aging bridges do not necessarily require replacement, they just need to be monitored for signs of corrosion and wear."

Neikirk and principal investigator and UT Civil, Architectural, and Environmental Engineering Chair Sharon L. Wood are developing a network of low-power wireless sensors capable of capturing and transmitting data to a central location. They already have working sensors, a data collection methodology, and specifications for sensor placement. Researchers are working on (1) powering sensors with solar, wind, or traffic vibrations instead of batteries, (2) ensuring the sensor output is compatible with National Instruments (NI) equipment that will be collecting the data and that NI equipment is rugged enough for outdoor use, and (3) preventing the steel structures from interfering with the radio signals used to transmit data.

[University of Texas at Austin]

Dr. Branko Glisic named Professor at Princeton University

The Department of Civil and Environmental Engineering at Princeton University announced the appointment of Dr. Branko Glisic as new assistant professor.

Branko joins Princeton University from SMARTEC SA, a Swiss company focused on structural health monitoring.  He joined SMARTEC in 2000, after receiving his PhD earlier that year from the Swiss Federal Institute of Technology – Lausanne (EPFL).  Branko holds degrees in Civil Engineering (1994) and Theoretical Mathematics (1996), both from the University of Belgrade.  His research interests include sensing and structural health monitoring, and smart structures and materials.

[Princeton.edu]

SAMCO Library of documents

The thematic network SAMCO (Structural Assessment, Monitoring and Control) has become a focal point of reference for industries (especially for small and medium sized enterprises), consultants and other organisations interested in the transfer of knowledge and technology in the field of assessment, monitoring and control of structures of relevant civil and industrial interest, in particular the transportation infrastructure. The activities of the network are mostly related to bridges, buildings, power plants and industries under seismic and other environmental loads. The knowledge and technology transfer supports the research community but also brings benefit to owners of structures, consultants, suppliers and end users.

SAMCO has an interesting library of documents that cover different aspects of Structural Health Monitoring and Bridge Management, in particular:

• Monitoring Glossary
  
• Ambient Vibration Monitoring
  
• Guidelines for Structural Control 
  

Smart bridges Research Project

Engineering smart bridges that can thoroughly discuss their health with inspectors is the goal of a new $19-million project led by the University of Michigan.

A year and a half after the I-35 bridge collapse in Minneapolis, the five-year project aims to create the ultimate infrastructure monitoring system and install it on several test bridges whose precise locations are not yet determined.

The monitoring system is envisioned to include several different types of surface and penetrating sensors to detect cracks, corrosion and other signs of weakness. The system would also measure the effects of heavy trucks on bridges, which is currently impossible. And through enhanced antennas and the Internet, the system would wirelessly relay the information it gathers to an inspector on site or in an office miles away.

Funded in large part by nearly $9 million from the National Institute of Standards and Technology's (NIST) Technology Innovation Program (TIP), the project involves 14 U-M researchers with the College of Engineering and the U-M Transportation Research Institute (UMTRI). In addition, engineers at five private firms in New York, California and Michigan are key team members. The remaining funding comes from cost-sharing among the entities involved and the Michigan Department of Transportation. MDOT has offered unfettered access to state bridges to serve as high-visibility test-beds showcasing the project technology.

"This project will accelerate the field of structural health monitoring and ultimately improve the safety of the nation's aging bridges and other infrastructures," said Jerome Lynch, principal investigator on the project and assistant professor in the Department of Civil and Environmental Engineering. "We want to develop new technologies to create a two-way conduit of information between the bridge official and the bridge. We are excited to collaborate on these transformative technologies with partners like MDOT who could use them immediately to improve bridge inspection processes."

Four types of sensors will contribute to gathering data. Victor Li, E. Benjamin Wylie Collegiate Professor of Civil and Environmental engineering, has developed a high-performance, fiber-reinforced, bendable concrete that's more durable than traditional concrete and also conducts electricity. Researchers would measure changes in conductivity, which would signal weaknesses in the bridge. On test bridges, the deck would be replaced with this concrete.

A carbon nanotube-based "sensing skin" that Lynch and a colleague in chemical engineering are developing would be glued or painted on to "hot spots" to detect cracks and corrosion invisible to the human eye. The skin's perimeter is lined with electrodes that run a current over the skin to read what's happening underneath based on changes in the electrical resistance.

Low-power, low-cost wireless nodes could look for classical damage responses like strain and changes in vibration. These nodes would harvest energy from vibrations on the bridge or even radio waves in the air. They are being developed by Dennis Sylvester, an associate professor in the Department of Electrical Engineering and Computer Science; and Khalil Najafi, Schlumberger Professor of Engineering, Arthur F. Thurnau Professor and chair of the Electrical and Computer Engineering division.

The fourth type of sensor would be housed in the vehicles that travel on the bridge. UMTRI researchers will outfit a test vehicle to measure the bridge's reaction to the strain the vehicle imposes. This information is not available today. But how vehicles, especially trucks, affect bridges is a critical piece of information that could help predict the structure's lifetime. Leading this effort is Research Professor Tim Gordon, head of UMTRI's Engineering Research Division.

[University of Michigan]

Wireless Monitoring of Highway Bridges

The nation's aging highway bridges could become safer structures using state-of-the-art wireless monitoring and inspection systems being developed through a multi-million-dollar grant to an engineering team from The University of Texas at Austin, National Instruments and Wiss, Janney, Elstner Associates, an engineering firm based in Northbrook, Ill.

The National Institute of Standards and Technology recently awarded the research team $3.4 million to develop the bridge monitoring systems. Including matching funds, the budget for the five-year research project doubles to about $6.8 million.

Civil, electrical and mechanical engineers from the Cockrell School of Engineering will work with engineers from the collaborating companies to develop two wireless monitoring systems. The work will draw on strengths in structural engineering and innovation in the school where faculty have an international reputation for successful large-scale laboratory testing and field monitoring of bridges.

The United States has about 600,000 highway bridges. Twenty-five percent were rated as structurally deficient or functionally obsolete in 2007, according to the Federal Highway Administration. About one-third of all bridges are 50 years or older.

Sharon L. Wood, the principal investigator and the chair of the Department of Civil, Architectural and Environmental Engineering, said the award will allow for the development of two wireless network systems that together will address a critical issue for bridge safety—the monitoring of cracks or defects and corrosion in key structural components.

"This project will not only transform the evaluation practices used for highway bridges today, but will dramatically advance the state of the art in wireless sensing technology," Wood said.

The group will first develop a system for existing bridges consisting of a network of low-power, wireless sensors designed to continuously monitor bridges deemed fracture-critical—those susceptible to collapse from the failure of a single critical component. The sensor nodes will harvest their own energy via solar or wind energy or vibrations in the bridge structure, Wood said, freeing them from the electric power grid. The nodes will be capable of supporting multiple sensors and will have sufficient computing power to process raw sensor data, detect events, and send notifications to a central, off-site location when a level of damage occurs.

"What we'll be doing is real-time monitoring of the bridge," Wood said.

The researchers will develop a second system to embed in new bridges as they are built. This system will consist of passive sensors designed to detect early signs of corrosion—the most common type of damage which cannot be seen by visual inspection—in reinforced concrete bridge decks. The sensors can be read using a wireless connection during regular bridge inspections. These robust sensors are inexpensive to produce, require no power source other than the wireless signal, can easily be dispersed throughout the entire structure during construction and will function for the lifetime of the bridge.

[University of Texas at Austin]