Recently, bridge collapses due to brittle fracture of grouted post-tensioning externaltendons have been reported, highlighting the importance of structural health monitoring toprevent and predict these situations that strongly compromise safety. Non-destructive testingtechniques based on the vibration response have proven their reliability in this aspect, as theyallow continuous monitoring of the tendon modal parameters and the estimation of tensionforce. The tension force can be indirectly estimated from the modal properties of the tendon.A simplified method to track the tension force is proposed, which consists of calibrating thetendon model by obtaining the equivalent modal lengths for each natural frequency in such away that general boundary conditions are considered for each mode. This study proposes a firstnumerical validation of this method through a detailed finite element model of a tendon. Thefinite element tendon model is subjected to a given stressing force; the bending stiffness andall other relevant parameters of the tendon are also known, subsequently, a modal analysis isperformed to obtain the natural frequencies. The first twenty natural frequencies numericallycalculated are then used to estimate the tension force based on the simplified method presentedpreviously, the modal length calibration and optimization for each natural frequency is carriedout for this example, and the estimated tension force and bending stiffness can be obtained.These results are compared with the finite element model of the tendon and then, the proposedtension force estimation procedure can be validated
Recently, bridge collapses due to brittle fracture of grouted post-tensioning externaltendons have been reported, highlighting the importance of structural health monitoring toprevent and predict these situations that strongly compromise safety. Non-destructive testingtechniques based on the vibration response have proven their reliability in this aspect, as theyallow continuous monitoring of the tendon modal parameters and the estimation of tensionforce. The tension force can be indirectly estimated from the modal properties of the tendon.A simplified method to track the tension force is proposed, which consists of calibrating thetendon model by obtaining the equivalent modal lengths for each natural frequency in such away that general boundary conditions are considered for each mode. This study proposes a firstnumerical validation of this method through a detailed finite element model of a tendon. Thefinite element tendon model is subjected to a given stressing force; the bending stiffness andall other relevant parameters of the tendon are also known, subsequently, a modal analysis isperformed to obtain the natural frequencies. The first twenty natural frequencies numericallycalculated are then used to estimate the tension force based on the simplified method presentedpreviously, the modal length calibration and optimization for each natural frequency is carriedout for this example, and the estimated tension force and bending stiffness can be obtained.These results are compared with the finite element model of the tendon and then, the proposedtension force estimation procedure can be validated Read More
Related posts:
Tension estimation of external post-tensioning tendons using machine-learning-based models
Tension Force Estimation of Post-tensioning External Tendons Through Vibration-Based Monitoring: Experimental Validation
Numerical study on the dynamic response of external post-tensioning tendons under strand breakages
Vibration-Based Monitoring for Non-destructive Testing of Post-tensioning External Tendons
Long-Term Dynamic Monitoring of Post-Tensioning External Tendons: Temperature Effect Evaluation
Simplified mechanical modelling of external grouted post-tensioning tendons under corrosion conditions