Experimental modal analysis and finite element model updating for structural health monitoring of reinforced concrete radioactive waste packages

Abstract This study envisages the use of modal analysis for monitoring the structural health of radioactive waste packages. To this end, the calibration of a numerical model that describes the dynamic behavior is a critical issue for the success in damage detection. In this study, experimental modal analysis was conducted on a radioactive waste package mockup. The container was tested under different boundary conditions. Then, the experimental modal analysis data was used to update finite element models that describe the observed behaviors. The latter consists in the formulation of an optimization problem that minimizes the differences between the experimental and the numerical data. A two-step methodology is proposed for finite element model updating. First, a full factorial design of experiments allowed estimation of a set of parameters of the numerical model that minimize a cost function. Second, a genetic algorithm was conducted, wherein the initial population of parameters was generated as a function of that set of parameters obtained in the previous step. This study serves as preliminary step towards the implementation of a structural health monitoring based on modal analysis. Specific aspects for the implementation of a modal-based structural health monitoring system in a radioactive waste repository are also summarized.