Daniel Meloni

Finite Element Modelling of Acoustic Waves Propagation in Stone Masonry

Abstract. The paper deals with the finite element modelling of acoustic waves propagation through a stone masonry specimen. In the last decades major efforts have been devoted to improve Sonic and Ultrasonic analysis of structural members and provide suitable correlations between acoustic wave features and the material parameters. This paper concerns the ultrasonic analysis and tomography of a masonry specimen made of trachyte blocks and cement mortar, including an inner void as an anomaly supposed to be detected by the analysis. The tests were performed with several equipments accordingly to the Direct Transmission Technique, transmitting an ultrasound signal by a piezoelectric transducer and detecting and analysing the signal received on the opposite side by another transducer. Basically the transmission time of the signal through an ideal path from the emitting and receiving transducers and the resulting wave speed are regarded as the main phenomenological measurements for non-homogeneity and anomalies detection.

Non Linear Fem Modelling for the Design of Openings in Masonry Walls

Countries like Italy have to face the constant issue of preserving and renewing existing buildings, both for the sake of conservation of the architectural and monumental heritage and due to the need of requalification and reuse. Considering the seismic hazard of most of Italian regions, structural interventions need to be carefully evaluated since National Codes don’t allow any sort of weakening of buildings and conversely regard any structural intervention as an opportunity to improve existing building safety. Most of existing and historical buildings in Italy are masonry structures, whose functional and architectonical requalification usually consists of new openings in masonry walls, but, according to the above mentioned principles, these modifications need to be designed at least without significantly affecting the pre-existent structural behavior. Thus, steel or reinforced concrete frames are to be designed in order to restore the previous conditions of masonry integrity. In this paper FEM analyses are performed and discussed in order to achieve this goal.