Smart Sensing Technology for Infrastructure Monitoring Supported by FHWA and USDOT Nizar Lajnef, Imen Zaabar, Shantanu Chakrabartty and Neeraj Buch Michigan State University
Moore s Law and Structural Health Monitoring Cost ($) 10 4 10 2 10 0 Chakrabartty, Feng, Aono, SPIE 2013. million silicon transistor pavement concrete (lb) structural concrete (lb) structural steel (lb) aluminum (lb) titanium (lb) passive RFID tag 10-2 Data Source: U.S. Geological Survey, ICKnowledge. 1980 1985 1990 1995 2000 2005 2010 2015 Year Economically viable to embed a million transistor IC in every concrete brick, on a pound of titanium alloy, a pound of steel,
Sensing Issues in Civil Structural Health Monitoring Cost Size Power Source Maintenance Maintenance free sensors Data meaning and interpretation Ease of installation and use Data type and format Integration with existing management systems Extreme events monitoring
Two Technologies Long-term Tagging Technology Events Detection and Condition Monitoring Technology
Pavement Tagging Technology PCC Mixture Design Inputs Cement Content (lbs) Type of cement Supplementary Cementitious Materials (lbs) Type of SCM Coarse Aggregate (lbs) Aggregate Geology Coefficient of thermal expansion Fine Aggregate (lbs) Aggregate Geology Water (lbs) Admixture(s) (fl.oz) Type of admixture(s)
Pavement Tagging Technology Fresh Concrete Properties Slump (inches) Unit Weight (lb/ft 3 ) Concrete Temperature ( O F) Entrained Air (%) Hardened Concrete Properties Compressive Strength (psi) Flexural Strength (psi) Elastic Modulus (psi) Measure CTE Construction Ambient Temperature at the time of concrete placement ( O F) Relative Humidity at the time of concrete placement (%) Wind Speed (mph) Curing material
Pavement Tagging Technology Pavement Design Slab thickness (inches) Base thickness (inches) Base type Subbase thickness (inches) Subbase type Resilient Modulus of base (psi) Resilient modulus of subbase (psi) Modulus of subgrade reaction (psi/in) Type of subgrade Joint spacing Joint sealant type Dowel diameter Dowel spacing Dowel bar material
Pavement Tagging Technology
Pavement Tagging Technology
Pavement Tagging Technology
DEMO
Two Technologies Long-term Tagging Technology Events Detection and Condition Monitoring Technology
MSU PFG Technology Sensors embedded inside smart structures that can self-prognosticate damage and mechanical failure. Zero Maintenance Sensors: Operational life of sensors comparable to the useful life of the structure Powering is one of the key challenges. Sensor Size and Powering
Damage Sensors Material Damage area Measured Strain Distributions Measured Strain Distributions relative shift Strain level Time * time Further from damaged area = less effect = smaller shift shift Strain level * time Time Measured Strain Distributions Strain level * Time time Am plit ude Δ 6 (1) Δ 5 (1) Δ 4 (1) Δ 3 (1) Δ 2 (1) Δ 1 (1) Δ 3 (2) Δ 2 (2) Δ 1 (2) Δ 1 (3) S 6 S 5 S 4 S 3 S 2 S 1 Cu mul ativ e Loa din g Tim e Δ 1 (i) S 1 Δ 2 (i) Δ 3 (i) S 2 Δ 4 (i) S3 S 4 Δ S 5 (i) 5 Δ S 6 6 (i) Time Strain Level Data compression Protocol
piezo 16 Piezo-floating-gate technology (US Patents: 7,757,565 and 8,056,420) Eliminate power regulators, energy storage, data converters, RAMs and digital signal processors. Use the physics of the device and the structure to perform computation and storage (Use analog computation instead of digital). Transducer piezoelectric Sensor IC Use Interface physics for sensing computation and storage current source drain Inject Floating gate Piezoelectric ceramics and polymers can generate high-voltages for low strain-levels but at ultra-low-driving currents.
Microwatt Barrier Comparison with other technologies MicaZ IRIS WISP Microstrain PFG 10-2 10-3 10-4 10-5 10-6 W Process Size Maximum Current consumption 0.5-μm standard CMOS 1900μm x 1500μm 110nA (7-channel level crossing monitoring) 90nA (3-channel impact monitoring) 17
100 Data Recording Protocol on the sensor 10 80 8 Strain ( ) ( ) 60 40 Voltage (V) 6 4 20 2 0 0 10 20 30 40 50 Time (ms) 0 0 10 20 30 40 50 Time (ms) 90 Recorded data on the sensor Cumulative active time (Number and duration of events) 80 70 60 50 40 30 20 10 0 1 2 3 4 5 6 7 Memory cells (Programmed strain levels)
Road-map: One sensor multiple Modalities Long-term Usage Monitoring Seismic Monitoring Usage Monitoring Pavements Tamper - detection Change Detection Supply-chain Monitoring Impact detection Intrusion Detection
Challenges: Size Attachment to the host structure Location Meaning of data Data interpretation and prognosis methods
Pavement Monitoring System (a) (b) (c) (d) Matching Element PFG Chip At Turner-Fairbanks Highway Research Facility. (e)
Manufacturing
Data Interpretation - Damage
Output Voltage Voltage (V) Data Interpretation - Damage Cumulative Distributions Variation 6 5 4 3 2 1 0 600 700 800 900 1000 1100 1200 1300 1400-1 Strain (με) 10 000 20 000 30 000 40 000 50 000 60 000 70 000 80 000 90 000 100 000 120 000 140 000-0.2 Normalized Density Distributions 1 0.8 0.6 0.4 0.2 0 600 800 1000 1200 1400 Strain (µɛ) 10,000 Cycles 140,000 Cycles Density 1.5 1 0.5 40 50 Probability distribution of the damage index versus the number of cyclic loading events. 0 0 0.5 20 30 1 10 Number of Cycle (thousand) Damage Index 1.5 0
Mean of the Damage Index Distribution 1 0.9 0.8 0.7 0.6 0.5 0.4 Data Interpretation - Damage Using the Sensnor Evaluated Using the COD Gage 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 Normalized Time Example - Variation over time of the mean damage index (from sensor) versus the damage index evaluated using data from a COD gage. Standard Deviation of the Damage Index Distribution 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0.04 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 Normalized Time Example - Variation over time of the standard deviation of the damage index distribution. Actual remaining life Predicted remaining life using the sensor 391 325 420 425 9350 7125 7022 11048 10980 23011 Predictions for example specimens
Asphalt concrete sample: Length: 18 (457.2 mm) Span length: 15 (381 mm) Thickness: 6.5 (165.1 mm) Width: 6 (152.4 mm) - Damage states: Intact: a= 0 mm Damage 1: a = 7/8'' (22.2 mm) Damage 2: a = 1 1/4'' (31.75 mm ) Damage 3 (crack propagation): a = 1 3/4'' (44.45 mm) Single Edge Notched Beam Test S 1 S 3 The crack propagation phase during the test 12.7 mm
Damage Detection Based on the FE Results Damage Detection Based on the Experimental Results (0.2 mm, 5 Hz)
Voltage Droppage (%) Voltage Droppage (%) Voltage Droppage (%) Voltage Droppage (%) Voltage Droppage (%) Voltage Droppage (%) 30% 25% Gate 1 30% 25% Gate 2 30% 25% Gate 3 20% 20% 20% 15% 15% 15% 10% 10% 10% 5% 5% 5% 0% Intact D1 D2 D3 D4 Damage 0% Intact D1 D2 D3 D4 Damage 0% Intact D1 D2 D3 D4 Damage 30% Gate 4 30% Gate 5 30% Gate 6 25% 25% 25% 20% 20% 20% 15% 15% 15% 10% 10% 10% 5% 5% 5% 0% Intact D1 D2 D3 D4 Damage 0% Intact D1 D2 D3 D4 Damage 0% Intact D1 D2 D3 D4 Damage
Looking into the Future Internet-of-Things and Big Data Integration. Vehicle-to-Infrastructure Communication Reader Self-powered Sensor Array 3G/4G mobile BIG DATA Cloud 3G/4G mobile 3G/4G mobile LAN Highway Management and Planning Software Reader Reader Self-powered Sensor Array Self-powered Sensor Array Analysis Center Future Maintenance Scheduling
Smart Sensing Technology for Infrastructure Monitoring Supported by FHWA and USDOT Nizar Lajnef, Imen Zaabar, Shantanu Chakrabartty and Neeraj Buch Michigan State University