HHT-Based Procedure to Derive the Constitutive Model of Prestressed Bridges from Traffic-Induced Loads

The performance of prestressed bridges strongly depends on the condition of their prestressing cables. However, these structural components are concealed and cannot be assessed through visual inspections. Building on a previous introductory study, this paper investigates a methodology based on the Hilbert–Huang Transform (HHT), enabling the reconstruction of the nonlinear force–displacement constitutive behavior of prestressed bridges by analyzing the dynamic response induced by traffic loads. Due to its adaptability to complex behaviors, HHT is well suited to analyze short-time, nonstationary, and potentially non-linear signals and allows for the correlation of instantaneous deformation and tangent stiffness in a one-to-one relationship over time. A realistic numerical application is presented to demonstrate the potential of the proposed strategy and lay the groundwork for real-world structural health monitoring applications.