Random Decrement Technique (RDT) based decentralized computing approaches implemented in wireless sensor networks (WSNs) have shown advantages for modal parameters and data aggregation identification. However, previous studies of RDT-based approaches from ambient vibration data have usually assumed that the input excitation is a broad-band stochastic process modeled by stationary white or filte...

An extension of the modal overlap factor is introduced that includes ensemble variations and frequency averaging of plates and acoustic spaces. Uniformly and normally distributed variations of geometric and material parameters are considered. Using this modal overlap factor, approximate formulas are derived to identify the limit of predictability for the combined case of damping, ensemble varia...

In order to achieve a more accurate finite element (FE) model for an as-built structure, experimental data collected from the actual structure can be used to update selected parameters of the FE model. The process is known as FE model updating. This research compares the performance of two frequency-domain model updating approaches. The first approach minimizes the difference between experiment...

A two-step probabilistic structural health monitoring approach is used to analyze the Phase II experimental benchmark studies sponsored by the IASC–ASCE Task Group on Structural Health Monitoring. This study involves damage detection and assessment of the test structure using experimental data generated by hammer impact and ambient vibrations. The two-step approach involves modal identification...

This paper presents a study on active detection of internal damage based on numerical analysis of vibration dynamics in composites. Damageinduced variations of dynamic parameters are investigated both numerically and experimentally. Finite element method (FEM) is used to compute the modal parameters of composites with or without damages. Natural frequency, modal displacement, modal strain and s...

Health monitoring of engineering structures has gained a lot of interest over the last few years. Many engineering structures suffer damage and deterioration when exposed to various loading and environmental changes during their lifetime. This seriously affects structural performance and may even lead to catastrophic structural failures. Thus, inspection and testing of structural components for...

The parameters of the parametrized modal operators [p] and 〈p〉 usually represent agents (in the epistemic interpretation) or actions (in the dynamic logic interpretation) or the like. In this paper the application of the idea of parametrized modal operators is extended in two ways: First of all a modified neighbourhood semantics is defined which permits among others the interpretation of the pa...

In the first International Operational Modal Analysis Conference it was shown for the first time how transmissibility measurements can be used to identify modal parameters. The main advantage of this new technique is that it is no longer necessary to make the assumption that the inputs to the structure are white noise. The unknown operational forces can be arbitrary (colored noise, swept sine, ...

In operational modal analysis process of the rotating machinery, it is always difficult to adopt usual modal analysis methods in parameter correction because of the modal parameter identification problems caused by harmonic modes. A technique to distinguish harmonic and structural modes is proposed here, that is, through frequency domain decomposition (FDD) of the vibration signals power spectr...

The perception of modal and falsetto registers was analyzed in a material consisting of a total of 80 vowel sounds sung by 10 choir singers, 40 sung in modal register and 40 in falsetto register. These vowel sounds were classified by sixteen expert listeners in a force choice test and the number of votes for modal was compared with the voice source parameters (1) Closed Quotient (Qclosed)and (2...