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Modal testing

About: Modal testing is a research topic. Over the lifetime, 4047 publications have been published within this topic receiving 64772 citations.


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Journal ArticleDOI
TL;DR: In this article, the authors conducted extensive experimental investigations on the Golden Gate Bridge in San Francisco, California, to determine, using ambient vibration data, parameters of major interest in both wind and earthquake problems, such as effective damping, the three-dimensional mode shapes, and the associated frequencies of the bridge vibration.
Abstract: Extensive experimental investigations were conducted on the Golden Gate Bridge in San Francisco, California, to determine, using ambient vibration data, parameters of major interest in both wind and earthquake problems, such as effective damping, the three‐dimensional mode shapes, and the associated frequencies of the bridge vibration. The paper deals with the tests that involved the simultaneous measurement of vertical, lateral, and longitudinal vibration of the suspended structure; a subsequent paper addresses the measurement of the tower vibration. Measurements were made at selected points on different cross sections of the stiffening structure: 12 were on the main span and 6 on the side span. Good modal identification was achieved by special deployment and orientation of the motion‐sensing accelerometers and by summing and subtracting records to identify and enhance vertical, torsional, lateral, and longitudinal vibrational modes. In all, 91 modal frequencies and modal displacement shapes of the suspe...

193 citations

Journal ArticleDOI
TL;DR: In this paper, the authors used the operational modal analysis (OMA) to predict machine dynamic stability lobes, and through experimental validation, it was shown that some depths of cut that are stable with standard stability layers become unstable with dynamic stability layers.
Abstract: The stability of high-speed machining operations determines the reliability of machine tools and the quality of machined parts. Chatter-free cutting conditions are difficult to predict as they require accurately estimated dynamic modal parameters. A spectrogram analysis and impact tests for different configurations of the machine tools were conducted to compare the modal parameters at 0 rpm tests and during machining tests. Variations of between 2% and 8% were observed for the natural frequencies and between 2 and 10 times for the damping ratios. The operational modal analysis (OMA) is considered as a powerful tool for dynamic modal parameter estimations during machining operations. A complete methodology for applying this technique for machining operations was detailed. It was demonstrate how the OMA can be industrially exploited. The proposed approach was successfully applied during the high-speed machining of the 7075-T6 aluminum alloy to extract machine-tool parameters. Two different numerical approaches were used: the autoregressive moving average method (ARMA) and the least square complex exponential method (LSCE), both of which generated similar results. The dynamic parameters found using the operational modal analysis were used to predict machine dynamic stability lobes, and through experimental validation, it was shown that some depths of cut that are stable with standard stability lobes become unstable with dynamic stability lobes.

184 citations

Journal ArticleDOI
TL;DR: In this paper, a sensitivity-based method is proposed for the scaling of operational mode shapes on a basis of operational modal models only, where the excitation forces are unknown and not all modal parameters can still be estimated.

173 citations

Journal ArticleDOI
TL;DR: In this paper, the authors presented the experimental and analytical modal analysis of a steel-girder arch bridge, which was carried out by ambient vibration testing under traffic and wind-induced excitations.
Abstract: The paper presents the experimental and analytical modal analysis of a steel-girder arch bridge. The field test is carried out by ambient vibration testing under traffic and wind-induced excitations. Both the peak picking method in the frequency domain and the stochastic subspace identification method in the time domain are used for the output-only modal identification. A good agreement in identified frequencies has been found between the two methods. It is further demonstrated that the stochastic subspace identification method provides better mode shapes. The three-dimensional finite element models are constructed and an analytical modal analysis is then performed to generate natural frequencies and mode shapes in the three-orthogonal directions. The finite element models are validated to match the field natural frequencies and mode shapes. It is observed that the finite element Model-2 with the concrete slab provides the greater stiffness in the transverse direction of the bridge. The finite element Model-1 with the lumped masses agrees well with the field tests and can serve as a baseline model of the bridge. DOI: 10.1061/~ASCE!0733-9445~2004!130:7~1022! CE Database subject headings: Modal analysis; Model tests; Experimentation; Vibration; Bridges, steel; Bridges, arch.

172 citations

Journal ArticleDOI
TL;DR: In this paper, the calibration of the numerical model of a bowstring-arch railway bridge based on modal parameters was performed using a genetic algorithm that allowed obtaining the optimal values of fifteen parameters.

166 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202367
2022164
202141
202059
201967
201878