Operational modal analysis for damage detection of a masonry construction

Abstract

This paper presents a dynamic identification analysis of a masonry construction, built to be tested in “Laboratório Nacional de Engenharia Civil” (LNEC), in Lisbon, on the scope of the European Project ECOLEADER-LIS – Enhancing Seismic Resistance and Durability of Natural Stone Masonry. The masonry model was built with limestone units and lime mortar joints with polymeric grid reinforcement placed on the horizontal joins. The dynamic identification analysis was divided in several tasks. For the calculation of the expected dynamic parameters a preliminary FEM analysis was carried out. Two types of operational modal analysis were used, the EFDD and SSI methods. The main purpose of the analysis was to compare the classical modal analysis with the ambient based modal analysis and to verify if the ambient vibration methods are able to assess the damage in an earlier stage in the structure. Finally, concluding remarks of the work carried out are given.