In mechanical engineering, random vibration is motion which is non-deterministic, meaning that future behavior cannot be precisely predicted. The randomness is a characteristic of the excitation or input, not the mode shapes or natural frequencies. Some common examples include an automobile riding on a rough road, wave height on the water, or the load induced on an airplane wing during flight. Structural response to random vibration is usually treated using statistical or probabilistic approaches. Mathematically, random vibration is characterized as an ergodic and stationary process.
A measurement of the acceleration spectral density (ASD) is the usual way to specify random vibration. The root mean square acceleration (Grms) is the square root of the area under the ASD curve in the frequency domain. The Grms value is typically used to express the overall energy of a particular random vibration event and is a statistical value used in mechanical engineering for structural design and analysis purposes.
Typical random vibration in the time domain
While the term power spectral density (PSD) is commonly used to specify a random vibration event, ASD is more appropriate when acceleration is being measured and used in structural analysis and testing.
Crandall[1][2][3][4] is uniformly considered as the father of random vibrations (see also books by Bolotin,[5]Elishakoff et al.[6][7][8]).
Test specifications can be established from real environment measurements using an ASD envelope or a fatigue damage equivalence criterion (Extreme response spectrum and Fatigue damage spectrum). Random vibration testing is one of the more common types of vibration testing services performed by vibration test labs. Some of the more common random vibration test standards are MIL-STD-810, RTCA DO-160, and IEC 60068-2-64.
^Crandall, S.H. (ed.), 1963, Random Vibration: Vol. 2, Cambridge, MA: MIT Press.
^Crandall, S.H., Mark, W.D.,1963, Random Vibration in Mechanical Systems, New York: Academic Press.
^Bolotin V.V, 1984, Random Vibrations of Elastic Systems, The Hague, The Netherlands: Martinus Nijhoff Publishers.
^Elishakoff, I., Lin, Y.K., Zhu, L.P., 1994, Probabilistic and Convex Modeling of Acoustically Excited Structures, Elsevier Science Publishers, Amsterdam, VIII + pp. 296; ISBN0-444-81624-0.
^Elishakoff, I, 2017, Probabilistic Methods in the Theory of Structures: Random Strength of Materials, Random Vibration, and Buckling, World Scientific, Singapore, ISBN978-981-3149-84-7, 2017.
^Elishakoff, I., 2018, Solution Manual to Accompany Probabilistic Methods in the Theory of Structures: Problems with Complete, Worked Through Solutions, World Scientific, Singapore, ISBN978-981-3201-10-1, 2018.
Random Vibrations, Spectral & Wavelet Analysis, D.E. Newland
Mechanical Vibration and Shock Analysis. Volume 3: Random Vibration, Second Edition, ISTE - Wiley, 2009.
External linksedit
NASA Goddard website about random vibration analysis
NASA Mars Orbiter website
January 01, 1970
random, vibration, mechanical, engineering, random, vibration, motion, which, deterministic, meaning, that, future, behavior, cannot, precisely, predicted, randomness, characteristic, excitation, input, mode, shapes, natural, frequencies, some, common, example. In mechanical engineering random vibration is motion which is non deterministic meaning that future behavior cannot be precisely predicted The randomness is a characteristic of the excitation or input not the mode shapes or natural frequencies Some common examples include an automobile riding on a rough road wave height on the water or the load induced on an airplane wing during flight Structural response to random vibration is usually treated using statistical or probabilistic approaches Mathematically random vibration is characterized as an ergodic and stationary process A measurement of the acceleration spectral density ASD is the usual way to specify random vibration The root mean square acceleration Grms is the square root of the area under the ASD curve in the frequency domain The Grms value is typically used to express the overall energy of a particular random vibration event and is a statistical value used in mechanical engineering for structural design and analysis purposes Typical random vibration in the time domain While the term power spectral density PSD is commonly used to specify a random vibration event ASD is more appropriate when acceleration is being measured and used in structural analysis and testing Crandall 1 2 3 4 is uniformly considered as the father of random vibrations see also books by Bolotin 5 Elishakoff et al 6 7 8 Contents 1 Random vibration testing 2 See also 3 References 4 External linksRandom vibration testing editTest specifications can be established from real environment measurements using an ASD envelope or a fatigue damage equivalence criterion Extreme response spectrum and Fatigue damage spectrum Random vibration testing is one of the more common types of vibration testing services performed by vibration test labs Some of the more common random vibration test standards are MIL STD 810 RTCA DO 160 and IEC 60068 2 64 See also editRandom noiseReferences edit Crandall S H ed 1958 Random Vibration New York MIT Press Wiley Crandell S H 1959 Random Vibration Applied Mechanics Reviews Vol 12 739 745 Crandall S H ed 1963 Random Vibration Vol 2 Cambridge MA MIT Press Crandall S H Mark W D 1963 Random Vibration in Mechanical Systems New York Academic Press Bolotin V V 1984 Random Vibrations of Elastic Systems The Hague The Netherlands Martinus Nijhoff Publishers Elishakoff I Lin Y K Zhu L P 1994 Probabilistic and Convex Modeling of Acoustically Excited Structures Elsevier Science Publishers Amsterdam VIII pp 296 ISBN 0 444 81624 0 Elishakoff I 2017 Probabilistic Methods in the Theory of Structures Random Strength of Materials Random Vibration and Buckling World Scientific Singapore ISBN 978 981 3149 84 7 2017 Elishakoff I 2018 Solution Manual to Accompany Probabilistic Methods in the Theory of Structures Problems with Complete Worked Through Solutions World Scientific Singapore ISBN 978 981 3201 10 1 2018 Random Vibrations Spectral amp Wavelet Analysis D E Newland Mechanical Vibration and Shock Analysis Volume 3 Random Vibration Second Edition ISTE Wiley 2009 External links editNASA Goddard website about random vibration analysis NASA Mars Orbiter website Retrieved from https en wikipedia org w index php title Random vibration amp oldid 1214373454, wikipedia, wiki, book, books, library,
