All aircraft vibrate and all components are designed, tested and certified to survive these vibration levels over their entire service life. Design standards such as MIL‐STD‐810F (1) and RTCA DO‐160E (2) are often used to obtain the vibration sign‐ off test; but what is the safety margin on these tests? How many hours do they represent on real aircraft? Can the equipment life b...

in this paper, full scale load test of a horizontally curved steel box-girder bridge is carried out in order to detect structural defects, which reportedly result in unwanted vibrations in nearby buildings. the bridge is tested under the passage of six heavy vehicles at different speeds, so as to determine its static and dynamic responses. a total number of one hundred and two (102) sensors are...

The tonal noise or vibration of air-cooled or water-cooled chillers with rotary twin screw compressors is crucial for environmental concerns. This work aims to perform the receiver tests regarding the radiated noise and structural vibration due to the compressor in different operating conditions. The sound pressure near the compressor is recorded by the one-third octave and narrow band frequenc...

structural dynamic parameters: natural period, shape modes and damping ratio of vibration, play a decisive role on the seismic behavior of those structures. there are several methods for determining of the structural dynamic parameters, such as: free vibration, ambient vibration and force vibration tests. in this research the structural response of a three-story building (the natural frequencie...

A literature review on the subject of ambient vibration testing is presented, and a review of a recent study to illustrate state-of-the-art in the application of the ambient vibration method. Reports on testing of full-scale structures by the ambient vibration method began to appear regularly around 1970, with about 3/4 of all contributions devoted to the experiments in buildings, dams, chimney...

The ambient and forced vibration techniques for testing full-scale structures are critically compared. Both methods, based on small level excitation, may be used to determine many mode shapes and frequencies of vibration and the corresponding damping values, with adequate accuracy for most purposes. The two techniques give mutually consistent results. The mode amplitudes determined by ambient a...

There is a worldwide interest in the proper design of embankment dams to resist earthquake loadings. For the first time in Iran, a complete ambient vibration survey due to low-level loads such as wind, machinery activities, low level tectonic activities, and water exit from bottom outlet was performed on Marun embankment dam. These kinds of ambient vibration tests are suitable for manifesting t...

There is a worldwide interest in the proper design of embankment dams to resist earthquake loadings. For the first time in Iran, a complete ambient vibration survey due to low-level loads such as wind, machinery activities, low level tectonic activities, and water exit from bottom outlet was performed on Marun embankment dam. These kinds of ambient vibration tests are suitable for manifesting t...