Damage severity estimation from the global stiffness decrease

12th International Conference on Damage Assessment of Structures

Nitescu, C.^1,2 ; Gillich, G.R.^1 ; Abdel Wahab, M.^3 ; Manescu, T.^1 ; Korka, Z.I.^1

NDT Laboratory, Faculty of Engineering and Management, Eftimie Murgu University of Resita, Romania^1

BMW AG, Munich, Germany^2

Laboratory Soete, Faculty of Engineering and Architecture, Ghent University, Belgium^3

关键词: Damaged beam;    Detection methods;    Different boundary condition;    Fracture mechanics approach;    Global stiffness;    Mathematical relation;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/842/1/012034/pdf
DOI  :  10.1088/1742-6596/842/1/012034

来源: IOP

【 摘 要 】

In actual damage detection methods, localization and severity estimation can be treated separately. The severity is commonly estimated using fracture mechanics approach, with the main disadvantage of involving empirically deduced relations. In this paper, a damage severity estimator based on the global stiffness reduction is proposed. This feature is computed from the deflections of the intact and damaged beam, respectively. The damage is always located where the bending moment achieves maxima. If the damage is positioned elsewhere on the beam, its effect becomes lower, because the stress is produced by a diminished bending moment. It is shown that the global stiffness reduction produced by a crack is the same for all beams with a similar cross-section, regardless of the boundary conditions. One mathematical relation indicating the severity and another indicating the effect of removing damage from the beam. Measurements on damaged beams with different boundary conditions and cross-sections are carried out, and the location and severity are found using the proposed relations. These comparisons prove that the proposed approach can be used to accurately compute the severity estimator.