Evaluation of Stiffness Loss Indicators Using Displacement Influence Lines for Homogeneous Beams

In this work, the simple beam and continuous beam with two spans—two popular types of beam structures—were examined under various conditions to assess the loss of stiffness of beams subjected to moving loads with the use of the influence line of displacement approach. The goal of this study is to identify damage (occurrence, position, and degree of stiffness deterioration) in beam structures using influence line displacement diagnostics in conjunction with finite element modeling to mimic structural behavior. A variety of damage evaluation indices are produced to assess the damage in the assessed beam based on the displacement influence line data that was received from the simulation results of various failure scenarios. Four indicators, including DAC (displacement assurance criterion), CC (correlation coefficient), RMSD (root-mean-square deviation), MAPD (mean absolute percentage deviation) are chosen for evaluation in this study. Based on displacement influence line data, the beam's damage evaluation indicators can locate parts with reduced stiffness. Results show that the displacement influence line approach works for diagnosing single damaged beams. However, in the case of multiple damaged elements, the approach necessitates a large number of displacement access points.