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51-1-10052-031
APPENDIX C
DYNA FORCE® ELASTO-MAGNETIC SENSOR
51-1-10052-031-R2-ACx/wp/ADY 51-1-10052-031
C-i
APPENDIX C
DYNA FORCE® ELASTO-MAGNETIC SENSOR
TABLE OF CONTENTS
FIGURES
DYNA Force® Elasto-Magnetic Sensor (Catalog Cut) Sheets 1 thru 8
DYNA Force® Elasto-Magnetic Sensor
Sheet 1 of 8
2
Penobscott Narrows Bridge and Observatory, Maine, USA
Sheet 2 of 8
General ..................................................................................................................... 4
Quality Assurance .................................................................................................... 5
Practical Applications ............................................................................................... 6
Contents
Sheet 3 of 8
4
General
On many occasions during construction and service life of the structure, it is crucial to know the force in the post-tensioning system. Although there are many methods to measure the tendon force, most of them are cumbersome, expensive, and the accuracy differs depending on the method used. DYWIDAG has been involved in the development, testing and execution of DYNA Force® to measure the force in the tendon. DYNA Force® is being used in cable stay bridges, cable system testing and building structure to measure the force during stressing and to monitor forces during the service life of the structure. DYNA Force® can be used for bare, epoxy-coated and greased-sheathed steel.
DYNA Force® is manufactured based on the theory that the permeability of steel to a magnetic field changes with the stress level in the steel. By measuring the change in a magnetic field the magnitude of the stress in the steel element can be obtained. The DYNA Force® does not alter the characteristics of the tendon other than its magnetization. The permeability is a function of temperature and magneti zation, and a calibration process eliminates the impact of these variables. The program takes into consideration the temperature change effect auto matically. A portable Power Stress unit is attached to wire leads from the DYNA Force®. This unit will create the magnetic field and then measure the residual value and then
convert it to a direct force reading. The accuracy of the force measurement is within 1%.DYNA Force® system is robust, requires no maintenance and has no moving parts. It is composed of sensors and Power Stress unit (read-out box). DYNA Force® is installed over the strand or bar during construction and a zero reading is taken before applying any post- tensioning force. It is expected to have a similar service life as the bridge/building structure. This will allow the owner to regularly monitor the forces in the post-tensioning system in minutes as a part of their inspection procedures without the need for lift-off equipment or other special expensive techniques. This will also avoid the inaccuracies and risks often associated with lift-off readings. One person can do this job.
Bar DYNA Force®
Strand DYNA Force®Power-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
Sheet 4 of 8
5
Quality Assurance
All DYNA Force® sensors are professionally made in a quality controlled facility. Furthermore, each DYNA Force® is tested and individually packed and numbered at the DSI facility before sending to the job site. Although many tests have been conducted in the development
of the DYNA Force®, DSI conducted additional tests to simulate the performance of the system when places within the anchorage zone of stay cables. In these tests DYNA Force® sensors were placed near the center and on the outside of the strand bun dle. The loads were applied using
a stressing jack and the force was monitored using a very accurate load cell. The load cell readings were compared to the results from the Power Stress unit and very good correlation was obtained.
Testing and Calibration of DYNA Force®
Sheet 5 of 8
6
Practical Applications
DYNA Force® in Cable Stay Anchor, Waldo, Maine, USA
When a DYNA Force® is installed on a strand/bar, the force in it may be obtained directly by merely attaching the leads from DYNA Force® to a portable Power Stress unit. No other equipment is needed. DYNA Force® sensors have been used in many bridge and building structures for the past several years.
DSI supplied two hundred forty sensors for Waldo cable stay bridge, Maine, USA. Each cable had six sensors and the cable forces at each stage of construction were monitored using these sensors. Periodic lift-off operations were made on the strands with sensors. A good correlation was observed. The bridge is now open to traffic and the forces in any cable can be monitored anytime using these DYNA Force® sensors without any disruption to traffic.
Sheet 6 of 8
7
Practical Applications
DSI used DYNA Force® sensors in a fatigue testing of 41-strand cable stay system. Force in each 0.6” dia epoxy coated strand was monitored at various loading stages during two-million fatigue cycles.
DYNA Force® in Fatigue Test of Cable Stay System
DYNA Force® sensors were used in moment resisting frames in a City Office building, California. The tendons
DYNA Force® for Seismic Evaluation of Building Structure, California, USA
were 0.5“ diameter greased and sheathed un-bonded strands. DYNA Force® was used to measure the force
during stressing and will be used to monitor the forces in each loop tendon especially after earthquake takes place.
Sheet 7 of 8
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 T A r I C A
C r O A T 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 A T 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 T A l Y
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 A T A 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
T A 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 A T 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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e.DYWIDAG-Systems International USA Inc.
320 Marmon Drive Bolingbrook, Il 60440 USAPhone (630)-739-1100 Fax (630)-739-5517E-Mail [email protected]
525 Wanaque Avenue, Suite ll1Pompton lakes, NJ 07442Phone (724) 869-0155Fax (973) 831-6503E-Mail [email protected]
1250 Connecticut Avenue, NW Suite 200Washington, DC 20036Phone (202) 263-4601Fax (866) 308-3832E-Mail [email protected]
3300 SW 50th Avenue Davie, Fl 33314 Phone (954)-318-1105Fax (954)-318-1107 E-Mail [email protected]
4732 Stone Drive, Suite ATucker, GA 30084Phone (770) 491-3790Fax (770) 938-1219E-Mail [email protected]
2400 hwy 287 N, Suite 106Mansfield, Tx 76063Phone (817) 473-6161Fax (817) 473-1453E-Mail [email protected]
3280 E. 59th Streetlong Beach, CA 90805Phone (562) 529-2109Fax (562) 529-2225E-Mail [email protected]
DYWIDAG-Systems International CANADA Ltd.
Eastern Division37 Cardico DriveGormley, ON l0h1G0Phone (905) 888-8988Fax (905) 888-8987E-Mail [email protected]
Quebec OfficeC.P. 412St. Bruno, QuebecJ3v 5GBPhone (450) 653-0935Fax (450) 653-0977E-Mail [email protected]
Western Division19433 96th Av.Suite 103Surrey, BC v4N4C4Phone (604) 888-8818Fax (604) 888-5008E-Mail [email protected]
Calgary Office2816-21 Street N.E., Suite 204Calgary, Alberta T2E 6 z2Phone (403) 291-4414Fax (403) 250-5221E-Mail [email protected]
Please note:This brochure serves basic information purposes only. Technical data and information provided herein shall be considered non-binding and may be subject to change without notice. We do not assume any liability For losses or damages attributed to the use of this technical data and any improper use of our products. Should you require further information on particular products, please do not hesitate to contact us.
Sheet 8 of 8
