Glaser SMSST

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…formulate a forward-looking collaborative research program in Integrated Structural Health Monitoring (SHM) of key civil infrastructure - a major branch of pioneering research world-wide US-China Joint Task Force On Integrated Structural Health Monitoring A Strategic Program of US-China Research for the Next Decade US-China Joint Working Group S.D. Glaser H. Li M.L. Wang J. Ou

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Comprehensive Joint Program Developed to stimulate and guide the research community formulate joint proposals in high priority areas insure the common interests of both countries leverage the resources and strengths of both countries This project has been strongly endorsed and supported by the National Science Foundation (NSF) and the National Natural Science Foundation of China (NSFC).

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increase bi-national research in an orderly fashion help major funding agencies to prioritize smart structures and SHM in their budget allocations. Leading Investigators From Both Countries can –

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We Have Formulated a Comprehensive Plan to accelerate the development of integrated health monitoring of critical civil structures exposed to earthquake and wind hazards accelerate technology transfer through complementary research and data exchanges actively involve relevant industrial and government agencies provide training sessions for practicing engineers facilitate international student exchanges design stimulating educational courses for students

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Individual investigators and ad hoc joint research teams already exist. China and the United States are owners of large inventories of civil structures distributed over vast areas. Our economies are more intertwined than perhaps any other two in the world. Common interests exist in the effective management of national infrastructure inventories. US - driving force behind the research and development of new sensor technologies. China - leading in deployment of sensor technologies and data interpretation for monitoring real civil structures. Synergies of a Sino-U.S. Partnership

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JW2-3D is a newly developed tri-axial sensing device to measure three dimensional rate of acceleration change. The JW2-3D sensor relies on a coupled electro-magnetic dynamic oscillator; 1) convert analog acceleration into internal analog relative displacement; 2) rate of change of this signal sensed by coupled electro-magnetic circuitry. Jerk has many applications: earthquake-induced structural damage detection, high-speed elevators, monitoring of train wheels (losing contact with rail), as well as global positioning Talents from US and PRC can jointly accomplish research objectives difficult for either side alone. G. C. Lee, M. Tong, SUNY Buffalo X. S. Yang and X. Z. Qi of IEM of CEA supported by NSF (CMS-0414020) A New Sensor for Measuring the Rate of Change of Acceleration - JW-3D Jerk Sensor

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Key Civil Systems and Associated Hazards.

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Test-bed Opportunities Should be Identified and Used as Often as Possible Perhaps the most direct way to achieve these goals is to construct large-scale models in the laboratory. If we go directly to the field and instrument a complex structures, we will be at the whim of nature, waiting for the next earthquake or typhoon An ideal test-bed would be used to demonstrate - a complete sensing network robust wireless communications and long-lived power sources a linked fundamental model of what constitutes damage meaningful but solvable problems entire networks put through their paces hardware and software development in collaboration with all stakeholders that proposed performance metrics capture what practicing community cares about.

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Courtesy of Y.Q. Ni

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Future SHM Technologies are Highly Dependent on Sensing System Model Most important enabling technology for SHM has been the Mote comprehensive miniature sensing platforms transduction (sensing or actuation) signal processing computational power wireless communication combinable into large, organic networks allows dense, detailed sensing In particular, sensors and micro-circuitry made possible by micro electro-mechanical systems (MEMS) technology

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Health Monitoring System for ZhanJiang Bay Bridge (China) University of Illinois – Chicago

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Lifeline systems, including energy delivery (e.g. electricity, gas, and oil), water supply and sewage pipelines, and communication systems, are essential Little attention has been paid to systems to monitor the operating conditions of lifeline systems Systems typically cover large areas, understanding spatially distributed sensor networks is required Sayings of the Secretary

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Damage occurs locally, affects globally, requires dense sensing Little work has been done on sensor fusion for the required dense sensor networks installed in civil infrastructure systems Fundamental component of the path forward – develop clear definition of what performance states will be considered operational (i.e. “healthy”) versus those that will be considered as “failed” (i.e. damaged) Sayings of the Secretary

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Difficult to identify sensor technology needs without knowing where, under what measurement conditions, and for what kind of infrastructure we must contend with Few studies have addressed both the hardware and software aspects of SHM in an integrated manner. Sayings of the Secretary

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Ultimate Goal of SHM facilitate rational decision-making regarding the safety and reliability of a structure show proper actions to take when safety concerns raised.

Low-Cost Wireless Monitoring Systems: 

Low-Cost Wireless Monitoring Systems Collaboration between Xiamen University (Prof. Ying Lei), University of Michigan (Prof. Jerry Lynch), and Stanford University (Prof. Kincho Law) Install a dense array of wireless sensors on the Wu-Yuan Bay Steel Arch Bridge in Xiamen Wu-Yuan Bay Bridge, Xiamen, P. R. China Installation Location of Wireless Sensors () Time-history Comparison Wired Wireless First Mode (0.78 Hz) calculated from Wireless Data

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Damage Detection and Decision-Making Algorithms take data collected from a monitoring system distill out information of structure’s health state facilitates scheduling of maintenance initiation of damage repairs allows rational decisions on structural retrofitting

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Physics-Based Damage Detection Infer the physical characteristics of a system through correlation of models and experimental input/response data solve an inverse problem analytical models or Green’s functions very powerful but difficult method

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Data-Driven Direct Damage Detection avoids dependence on analytical models unsupervised learning limited to level one (i.e. existence) or level two (i.e. location) damage classification very effective for identifying the onset of damage growth

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Statistical Damage Detection all SHM/NDE are problems in statistical pattern recognition damage state inferred by comparing test data with baseline data dependence of damage diagnosis on the prior baseline data is a problem quantify effects of imperfect sensors

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Sensors Concepts MEMS-based devices are King! Smart materials - Research in three major areas advancements in fabricating transducing or “self-sensing” materials incorporating such materials into construction elements nanoengineered materials. Active sensing and power harvesting Usually SHM sensors are passive components “active” sensors intentionally introduce an excitation into the structure measures the corresponding structural response introduce controllable and repeatable excitations

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Sensor Transduction Technology “Fatigue” Effect Sensors Corrosion Effect Sensors Optical fiber sensors Photogrammetric Sensing Systems Scour Effect Sensor System Cable Force Measurement Sensor Integration

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Piezoelectric Paint Sensor of Ultrasonic based Damage Detection Y. Zhang, Lehigh University, and Lily Zhou, Nanjing University of Aeronautics and Aerospace; NSF award CMS-0442076. Piezoelectric paint sample Measured ultrasonic signal at paint (tone-burst, 100 kHz) A sprayable piezoelectric paint that uniformly cures at ambient temperature. It is a composite piezoelectric material with adjustable material properties. Composite properties can be tailored to specific requirements Applications: close-range ultrasonic based nondestructive evaluation, e.g. distributed acoustic emission sensor and ultrasonic guided wave-based embedded sensors in metal or fiber reinforced polymer composite Acoustic emission signal received by piezoelectric sensors in pencil break test

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Historical Note - China ~ US have a long-term comprehensive research collaboration in earthquake engineering. NSF is the American agency involved. Chinese Agencies that have been involved include the CEA, the MOC, and the NSFC. Unfortunately, these joint earthquake programs have had limited success. Key problem - lack of a dedicated research program that is collectively organized by both countries. Our view of US-China collaboration requires collective trans-Pacific organization.