Variation in modal properties of slender masonry structure due to damage

The paper aims at exploring possible changes in modal properties of masonry slender structures for damage identification. To this purpose, nonlinear numerical analyses have been conducted for the case studies of a tower and a slender barrel vault under their self-weight and some real seismic inputs, in order to represent real damage scenarios. Variations in natural frequencies, mode shapes and modal curvatures have been numerically evaluated and their sensitivity to damage occurrence investigated. The effectiveness of some criteria usually adopted to detect structural damage has also been verified.