DYNA Force® Elasto-Magnetic Force Monitoring System
There is an increasing demand for health monitoring systems for geotechnical applications as well as for bridges and buildings. For these structures, steel elements that are either prestressed or subject to high compression forces are key elements for achieving the scheduled performance of the structure. On many occasions during the construction and service life of a structure, it is of decisive importance to know the stress level / the axial forces of the steel elements in use. Although there are many methods to measure the axial force, most of them are cumbersome, expensive, and the accuracy varies depending on the method used.
DYWIDAG-Systems International actively participated in the development, testing and utilization of the DYNA Force® System for measuring the force in steel bars or strands.
The force measuring technique is based on the elasto-magnetic properties of ferromagnetic materials and is carried out using DYNA Force® Sensors. The magnetic permeability of steel in a magnetic field changes as a function of the mechanic normal stress condition of the steel. By measuring the relative change in magnetic permeability, the normal stress in the steel tendon can be determined. The DYNA Force® Monitoring System is based on the principle described above and can be used for bars, strands and wires.
The hollow cylinder monitoring sensors are available in different diameters to suit various bar and strand diameters.
A readout unit measures the magnetic permeability of the steel tendon through the sensor and shows the tendon force. Each DYNA Force® Sensor is fitted with an integrated temperature sensor in order to automatically compensate the influence of possible temperature alterations.
The DYNA Force® System allows the permanent monitoring of post-tensioning forces in steel tendons.
Force readings as part of inspection procedures can be done within a few minutes without the need for lift-off equipment or other cost-intensive techniques.
- Lifetime monitoring of the post-tensioning performance in structures
- Knowledge that their post-tensioning design is working as intended. The system permits posterior analysis and potential adjustment at any time in the future
- Monitoring of tendon forces at any time with alert warning
- Quality and support from the leading industry supplier
- Sensors can either be mounted in the factory or on site
- Typically, no extra work or interference with post-tensioning installations
- No large load cell at anchorages and no increased pocket depth
- Load check during stressing
- Increased construction site safety
- The electronic force readout is safe and reliable
- Easy connection with mobile devices by WiFi
- Can be controlled on-site (WiFi) or remotely (SimCard)