Magneto-Elastic Method |
The magnetic flux is related to the stress and temperature, and the cable force is calculated by measuring the magnetic flux. |
1.The cables with complex boundary conditions can be solved theoretically. |
1. Each cable has a unique relationship curve between the output voltage of the magnetic flux sensor and the cable force, so it must be calibrated before leaving the factory, which is time-consuming and laborious. |
Construction period and service period |
2. The mechanical and physical properties of the cable body will not be damaged. |
2. Long construction period required |
Resistance strain gauge measurement method |
There is a certain relationship between the resistance and strain of the resistance strain gauge. The cable body strain can be obtained according to the resistance change rate when the cable body is deformed, and the cable force can be calculated. |
1. The operation is simple and fast. |
1. The resistance method will cause irreversible damage to the cable surface and reduce the durability of the cable. |
construction period |
2. Low measurement cost. |
2. The measurement accuracy is average. |
3. The required construction period is short |
3. Unable to measure for a long time. |
Frequency measurement method |
Based on the principle of string vibration, the relationship between vibration frequency and cable force is determined, and the measured frequency is converted into cable force. |
1. Engineering is widely used and the method is mature. |
1. It is difficult to derive the cable force-frequency formula under complex boundary conditions. |
Construction period and service period |
2. The accuracy meets the requirements. |
2. It is difficult to pick up the frequency of the cable section. |
Clamp cable tension meter measurement method |
The strain is transmitted to the optical fiber sensor through the codeformation of the clamp and cable body, and then the stress is obtained by Hooke's law, and the cable force is calculated. |
1. The construction is simple and convenient. |
1. When the cable force of the cable body is small, the accuracy is low. |
Construction period (later period) and service period |
2. No damage to the cable body. |
2. At present, the accuracy of the construction process test needs to be improved.。 |
3. It does not affect the construction period and is easy to set up. |
3. The measurement accuracy is greatly affected by the degree of coordinated deformation of the clamp and cable body. |
4. Real-time monitoring can be realized with low cost. |
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Jack measuring method |
The tension of cable body is provided by jack. Reliable cable force can be obtained by installing an active oil pump and pressure gauges on the cable body. |
1. Simple and reliable cable force collection is realized in the construction process. |
1. During construction, relevant shutdown nodes need to be found to give the data recording time. |
construction period |
2. No additional equipment or facilities will be added. |
2. Cable forces cannot be tracked further after forming. |
Intelligent cable measurement |
During cable making, packaged optical fiber sensors are embedded in the cable body to obtain cable force through optical fiber sensing. |
1. The strain at any position of the cable body can be obtained to realize the distributed measurement. |
1. Higher costs. |
Construction period and service period |
2. High measurement accuracy. |
2. Long construction period is required, and the composite sensing ribs need to be embedded in advance when the cable is fabricated. |
3. Real-time monitoring. |
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