Bridge Monitoring Security and Smart Bridges

Transcription

1 Bridge Monitoring Security and Smart Bridges Brent Phares and Terry Wipf Iowa State University Nationa Center for Wood Transportation Structures and Bridge Engineering Center Mike Ritter USDA Forest Products Laboratory

2 Bridge Security Cooperative research project initiated by the USDA Forest Product Laboratory and Iowa State University. A critica need identified provide a eve of protection to historic covered bridges. Vandaism Arson

3 The Need in Madison County, IA

4 Initia Goas Deveop & demonstrate a prototype remote security system Assist in the preservation of important timber bridges Fi a gap in the FHWA Covered Bridge Manua.

5 First Generation System Configuration Three types of sensing systems: Infrared camera Fame detector Fiber optic temperature sensors Data coected and processed on-site. Aarms sent via text message and e- mai to ISU and emergency responders.

6 Infrared Camera Detects both peope and fire Mounted on utiity poe Sees IR spectrum rather than visibe ight

7

8 Fame Detector Detects presence of a fame using: infrared utravioet visua technoogies (ficker rate, etc.) Probabiity of fase aarm is very sma

9 Fiber Optics Measures temperature changes Length of sensor changes with temperature Instaed in bridge behind trusses

10 On-site System Data transmitted from sensors using onsite wireess network Software processes data from a sensors Records data (incuding images) for use by aw enforcement when aert issued

11 Notifications

12 Current Activities Second generation system currenty being depoyed on an additiona 5 bridges. A covered bridge security manua is currenty being deveoped.

13 Deveopment of a Smart Timber Bridge System Concept: A hoistic approach to timber bridge management through the integration of sensors and on-board computing. Initiay deveoped the scope of research needed for fu deveopment. Currenty in the first phase of that work.

14 Current Objective and Scope Objective Deveop methods for embedding in and attaching sensors to wood members. Scope Design two types of sensors packages:» One for structura adhesion.» One to isoate the sensor from structura response. Construction of sma scae guam specimens that are internay and externay instrumented. Laboratory testing of the specimens under different oading and temperature conditions. Seection of the best sensor packages. Construction of a fu scae beam specimen using seected packages and test under aboratory conditions.

15 Sma Scae Laboratory Testing Nine specimens tested under: Bending Sustained oading Fast oading Pseudo cycic oading Heat and sustained oading Cod and sustained oading

16 Structura Response Packages Externa Packages: C-FRP Loctite 426 RS-SS SS Loctite " 7 8 " " 7 8 " IS-SS SS Loctite H-SS Loctite " 1 2 " Interna Packages: " " 4 " " 4 " 1 2 " 1 8 " on center 1 4 " on center AM-SS Loctite 454 RS-SS SS Loctite " " 1" " 2" " 7 8 "

17 Sma Scae Test Setup 2500 bs Direction of oading SATEC head Pin connection 12" GLULAM Specimen Roer connection 36" SATEC Tabe C L

18 Fu Scae Beam

19 Fu Scae Beam Testing West End Mid Span Load Location 7" typica 4'-6" 4'-6" East End Sensors N.A. DCDT at neutra axis Span ength = Girder ength = 30' 31' DCDT on the bottom

20 Typica Resuts Strain Sensors Side 1 West End Side 1 Mid Span Side 1 East Ead Side 2 West End Side 2 Mid Span Side 2 East End: Strains [με] [με] MOE 1600 ksi Compressive atera Compressive midspan Tensie atera Tensie midspan Load [bs] [N] Load on Side 1 West Frame East Frame Time [sec]

21 Typica Resuts Strains [με] [με] Strain Sensors Side 1 West C-FRP Loctite 426 Mid Span C-FRP Loctite 426 Est 72H-SS Loctite 4212 Side 2 West RS-SS Loctite 426 Mid Span RS-SS Loctite 426 East IS-SS Loctite MOE 1600 ksi Compressive Tensie Load on Side 1 West Frame East Frame Load [bs] [N] Time [sec]

22 Questions? Thank you!