Bayesian inference of hidden corrosion in steel bridge connections: Non-contact and sparse contact approaches

This paper describes approaches for inferring the presence and nature of hidden corrosion occurring between connection plies in steel truss bridges. The proposed methods furnish, both non-contact and very sparse contact inspection modalities supporting this goal. The work is numerical in nature and involves the solution of stochastic inverse problems, in a Bayesian setting, in order to quantify uncertainty in modeling parameter estimation describing hidden corrosion (i.e. corrosion that cannot be directly visualized). A non-contact approach, involving a digital infrared camera, is described. Additionally, the paper also describes a means for employing so-called Gappy Proper Orthogonal Decomposition (Gappy-POD) in permitting a tiny number of contact temperature sensors to be applied for characterization of the same hidden corrosion. •Algorithmic means for characterizing steel bridge connection corrosion are given.•The corrosion considered is hidden section loss between connection plies.•Both non-contact and sparse contact means are pursued.