부산대학교 도서관

Tendon damage is a major risk of prestressed structures. Ground anchors are structural elements that introduce high levels of prestress, typically over 1000 kN. Tendon damage can threaten the stability of the structure they support. Particularly, the visual inspection of buried ground anchor tendons is impossible. Thus, assessing tendon damage is essential during its service life. In this study, an embedded tendon damage detection method based on the magnetostriction effect is developed. A parametric study was conducted to optimize the sensor parameters through numerical simulations based on the finite element method (FEM). Based on the results, the elasto-magnetic (EM) sensor was fabricated. Different damage degrees in tendons were measured at room temperature using the fabricated EM sensor. Subsequently, the induced electromotive force (EMF) and magnetic flux density were obtained. The finite element simulation results showed a quadratic relationship between the effective cross-sectional area reduction ratio (ARR) of the specimen due to damage and the peak of magnetic flux density. The experimental results were compared with the simulation results. This study introduces a promising nondestructive evaluation (NDE) method for detecting damage in the embedded tendon of ground anchors and demonstrates a design methodology for EM sensors suitable for the target object.