Abstract : The article aims at detecting and quantifying early structural damages using
deterministic and probabilistic model updating techniques. To achieve this purpose,
local information in a form of optical strain measurement is employed. The
strategy consists in updating physical parameters associated to damages, such
as Young’s modulus, in order to minimize the gap between the numerical strain
obtained from finite element solves and the strain sensor outputs. Generally,
the damage estimation is an ill-posed inverse problem, and hence requires regularization.
Herein, three model updating techniques are considered involving
different type of regularization: classical Tikhonov regularization, Constitutive
Relation Error based updating method and Bayesian approach.
An illustration of these three approaches is proposed for localizing and quantifying
an early damage in a real 8 meter post-tensioned concrete beam. Numerical
results show that all the methods properly localize the damaged area
and give similar estimation of the damage level