DSI DYNA Force Elasto-Magnetic Senso Us
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DYNA Force Elasto-Magnetic Sensor
description
DYNA
Transcript of DSI DYNA Force Elasto-Magnetic Senso Us
DYNA Force Elasto-Magnetic Sensor
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Penobscott Narrows Bridge and Observatory, Maine, USA
General ......................................................................................................................4
Quality Assurance .....................................................................................................5
Practical Applications ...............................................................................................6
Contents
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General
On many occasions during constructionand service life of the structure, it iscrucial to know the force in the post-tensioning system. Although there aremany methods to measure the tendonforce, most of them are cumbersome,expensive, and the accuracy differsdepending on the method used.DYWIDAG has been involved in thedevelopment, testing and execution ofDYNA Force to measure the force inthe tendon. DYNA Force is being usedin cable stay bridges, cable systemtesting and building structure tomeasure the force during stressing andto monitor forces during the service lifeof the structure. DYNA Force can beused for bare, epoxy-coated andgreased-sheathed steel.
DYNA Force is manufactured based onthe theory that the permeability of steelto a magnetic field changes with thestress level in the steel. By measuringthe change in a magnetic field themagnitude of the stress in the steelelement can be obtained. The DYNA Force does not alter the charac-teristics of the tendon other than itsmagnetization. The permeability is afunction of temperature and magneti-zation, and a calibration process elimi-nates the impact of these variables.The program takes into considerationthe temperature change effect auto-matically. A portable Power Stress unitis attached to wire leads from theDYNA Force. This unit will create themagnetic field and then measure theresidual value and then convert it to a
direct force reading. The accuracy ofthe force measurement is within 1%.DYNA Force system is robust, requiresno maintenance and has no movingparts. It is composed of sensors andPower Stress unit (read-out box). DYNA Force is installed over the strandor bar during construction and a zeroreading is taken before applying anypost-tensioning force. It is expected tohave a similar service life as the bridge/building structure. This will allow theowner to regularly monitor the forces inthe post-tensioning system in minutesas a part of their inspection procedureswithout the need for lift-off equipmentor other special expensive techniques.This will also avoid the inaccuraciesand risks often associated with lift-offreadings. One person can do this job.
Bar DYNA Force
Strand DYNA ForcePower-Stress Unit
DYNA Force Dimensions
DYNA Force Type Strand/Bar DYNA Force Dimensions
ID OD Length
[in] [in] [in]
Strand DYNA Force 0.5" 0.71 1.50 5.1
0.6" 0.78 1.50 5.1
Bar DYNA Force 1-1/4" & 1-3/8" 1.70 2.80 6.7
1-3/4" 2.10 3.90 8.3
2-1/2" 2.85 6.20 12
Note: Dimensions for 2-1/2" bar are preliminary
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Quality Assurance
All DYNA Forces are professionallymade in a quality controlled facility.Furthermore, each DYNA Force istested and individually packed andnumbered at the DSI facility beforesending to the job site. Although manytests have been conducted in the
development of the DYNA Force, DSIconducted additional tests to simulatethe performance of the system whenplaces within the anchorage zone ofstay cables. In these tests DYNAForces were placed near the center andon the outside of the strand bundle.
The loads were applied using a stress-ing jack and the force was monitoredusing a very accurate load cell. Theload cell readings were compared tothe results from the Power Stress unitand very good correlation wasobtained.
Testing and Calibration of DYNA Force
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Practical Applications
DYNA Force in Cable Stay Anchor, Waldo, Maine, USA
When a DYNA Force is installed on astrand/bar, the force in it may beobtained directly by merely attachingthe leads from DYNA Force to aportable Power Stress unit. No otherequipment is needed. DYNA Forceshave been used in many bridge andbuilding structures for the past severalyears.
DSI supplied two hundred forty sensorsfor Waldo cable stay bridge, Maine,USA. Each cable had six sensors andthe cable forces at each stage ofconstruction were monitored usingthese sensors. Periodic lift-offoperations were made on the strandswith sensors. A good correlation wasobserved. The bridge is now open totraffic and the forces in any cable canbe monitored anytime using theseDYNA Forces without any disruption to traffic.
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Practical Applications
DSI used DYNA Forces in a fatiguetesting of 41-strand cable stay system.Force in each 0.6” dia epoxy coatedstrand was monitored at variousloading stages during two-millionfatigue cycles.
DYNA Force in Fatigue Test of Cable Stay System
DYNA Forces were used in momentresisting frames in a City Officebuilding, California. The tendons were
DYNA Force for Seismic Evaluation of Building Structure, California, USA
0.5" diameter greased and sheathed un-bonded strands. DYNA Force wasused to measure the force during
stressing and will be used to monitorthe forces in each loop tendonespecially after earthquake takes place.
A U S T R I A
A R G E N T I N A
A U S T R A L I A
B E L G I U M
B O S N I A A N D H E R Z E G O V I N A
B R A Z I L
C A N A D A
C H I L E
C O L O M B I A
C O S TA R I C A
C R O AT I A
C Z E C H R E P U B L I C
D E N M A R K
E G Y P T
E S T O N I A
F I N L A N D
F R A N C E
G E R M A N Y
G R E E C E
G U AT E M A L A
H O N D U R A S
H O N G K O N G
I N D O N E S I A
I R A N
I TA LY
J A P A N
K O R E A
L E B A N O N
L U X E M B O U R G
M A L A Y S I A
M E X I C O
N E T H E R L A N D S
N O R W A Y
O M A N
P A N A M A
P A R A G U A Y
P E R U
P O L A N D
P O R T U G A L
Q ATA R
S A U D I A R A B I A
S I N G A P O R E
S O U T H A F R I C A
S P A I N
S W E D E N
S W I T Z E R L A N D
TA I W A N
T H A I L A N D
T U R K E Y
U N I T E D A R A B E M I R AT E S
U N I T E D K I N G D O M
U R U G U A Y
U S A
V E N E Z U E L A
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USA
DYWIDAG-SYSTEMS INTERNATIONAL USA INC.Headquarter Americas320 Marmon DriveBolingbrook, IL 60440Phone: (630) 739-1100Fax: (630) 972-9604E-Mail: [email protected]
DYWIDAG-SYSTEMS INTERNATIONAL USA INC.Post-Tensioning & Reinforcement525 Wanaque AvenuePompton Lakes, NJ 07442Phone: (973) 831-6560Fax: (973) 831-6503E-Mail: [email protected]
DYWIDAG-SYSTEMS INTERNATIONAL USA INC.#1808 N. Peyco DriveArlington, TX 76001-6704Phone: (817) 465-3333Fax: (817) 465-3696E-Mail: [email protected]
DYWIDAG-SYSTEMS INTERNATIONAL USA INC.5220 Clark AvenueSuite 220Lakewood, CA 90712Phone: (562) 263-0256Fax: (562) 263-0285E-Mail: [email protected]
DYWIDAG-SYSTEMS INTERNATIONAL USA INC.4732 Stone DriveTucker, GA 30084Phone: (770) 491-3790Fax: (770) 938-1219E-Mail: [email protected]
Canada
DYWIDAG-SYSTEMS INTERNATIONAL CANADA LTD.Eastern Division37 Cardico DriveGormley, ON L0H1G0Phone: + 1-905-888-8988Fax: + 1-905-888-8987E-Mail: [email protected]
DYWIDAG-SYSTEMS INTERNATIONAL CANADA LTD.Western DivisionSuite 10319433 96th Av.Surrey, BC V4N4C4Gormley, ON L0H1G0Phone: + 1-604-888-8818Fax: + 1-604-888-5008E-Mail: [email protected]
