Numerical study on the dynamic response of external post-tensioning tendons under strand breakages

Resumen

Non-destructive testing (NDT) techniques based on vibration methods can be used to detect anomalies in external post-tensioning tendons. In this sense, a numerical study on the dynamic response of a tendon is carried out under strand breakages. In order to quantify the sensitivity of several performance indicators (PIs) to strand breakage. The indicators are: the natural frequencies, the ratios between them and the modal shape symmetry. Thus, firstly, the partial differential equation that governs the cable displacement including bending stiffness is solved. Secondly, a detailed 3D finite element (FE) model of a seven-strand tendon is developed. An elastic contact model between strands and grout has been assumed. Finally, the performance indicators together with the effective tension force are assessed for the simulation steps in such a way that their effectiveness as damage indicator tool for vibration-based NDT is assessed.