Implementation of OMA procedures using LabView: Theory and Application

During the last years, a number of techniques aimed at the experimental identification of the dynamic characteristics of structures has been developed. Their use has progressively extended to various fields, such as aerospace, automotive and civil structures. Besides the traditional techniques based on input knowledge, increasing interest is observed for techniques based on environmental vibrations that do not need any expensive excitation device. Among the methods for the evaluation of the relevant dynamic parameters of structures under service conditions, some of them works in the time domain (Least Square Complex Exponential, Ibrahim Time Domain, etc.) and others in the frequency domain (Frequency Domain Decomposition, etc.). In this paper some theoretical aspects of OMA methods are reviewed: in particular, attention is focused on frequency domain and time domain methods aimed at highlighting opportunities given by well-known tools like LabView Virtual Instruments. Some aspects related to the implementation of a OMA based software are therefore discussed. Furthermore, an application is briefly reported based on the data recorded on a real structure, the School of Engineering Tower in Naples and an evaluation of computational effort of different software architectures is presented.