Dynamic investigation of an ancient masonry bell tower with operational modal analysis: a non-destructive experimental technique to obtain the dynamic characteristics of a structure

This paper shows the results of an experimental analysis on the bell tower of “Chiesa della Maddalena” (Mola di Bari, Italy), to better understand the structural behavior of slender masonry structures. The research aims to calibrate a numerical model by means of the Operational Modal Analysis (OMA) method. In this way realistic conclusions about the dynamic behavior of the structure are obtained. The choice of using an OMA derives from the necessity to know the modal parameters of a structure with a non-destructive testing, especially in case of cultural-historical value structures. Therefore by means of an easy and accurate process, it is possible to acquire in-situ environmental vibrations. The data collected are very important to estimate the mode shapes, the natural frequencies and the damping ratios of the structure. To analyze the data obtained from the monitoring, the Peak Picking method has been applied to the Fast Fourier Transforms (FFT) of the signals in order to identify the values of the effective natural frequencies and damping factors of the structure. The main frequencies and the damping ratios have been determined from measurements at some relevant locations. The responses have been then extrapolated and extended to the entire tower through a 3-D Finite Element Model. In this way, knowing the modes of vibration, it has been possible to understand the overall dynamic behavior of the structure.

Neutrosophic and Modal Components of Relations in Complex Systems

Semiotic components in the relations of complex systems depend on the Subject. There are two main semiotic components: Neutrosophic and Modal. Modal components are alethical and deontical. In this paper the authors applied the theory of Neutrosophy and Modal Logic to Deontical Impure Systems.

Selected topics in algebraic geometry; report of the Committee on rational transformations:

Bibliography at end of each chapter.

Transformations of heavy metals and plant nutrients in dredged sediments as affected by oxidation reduction potential and pH : final report /

"May 1977."

Metrical geometry, contact transformations and nuclear physics.

Cover title.

Development of a systems risk methodology for single and multi-modal transportation systems. Final report.

Transportation Department, Research and Special Programs Administration, Washington, D.C.

Modal cities /

Includes bibliographical references.

Analysis of intercity modal split models. Final report.

Transportation Department, Office of the Assistant Secretary for Policy and International Affairs, Washington, D.C.

Trends in federal transportation financial activity, fiscal years 1970-1979 : report number 2, modal distribution of federal transportation obligations and outlays /

"April 1980."

Graph transformations for composite formation,

"C00-1018-1195."

Transformations on loop-free program schemata.

Thesis--University of Illinois.

Essai sur l'anatomie pathologique en général, et sur les transformations et productions organiques en particulier /

Mode of access: Internet.

L'empire carolingien, ses origines et ses transformations,

"Bibliographie": p. [v]-xvi.