Eigenfrequency of hydraulic systems belongs to important dynamic quantities.
Vašina Martin, Hružík Lumír, Bureček Adam 2016, 'Eigenfrequency of Hydraulic Systems of Loading Device', EPJ Web of Conferenceshttp://dx.doi.org/10.1051/epjconf/201611402131. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
Their eigenfrequency and maximum piezoelectric power output are analyzed by the experiment and simulation.
Lu Wang, Dejiang Lu, Zhuangde Jiang, Chen Jia, Yumeng Wu, Xiangyang Zhou, Libo Zhao,Yulong Zhao 2018, 'A piezoelectric cantilever with novel large mass for harvesting energy from low frequencyvibrations', AIP Advanceshttp://dx.doi.org/10.1063/1.5044558. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
From these vibrations we have determined the bars damping factor and eigenfrequency.
Cosmin Mihai MIRITOIU, Cristian Oliviu BURADA, Marius Marinel STANESCU, AlexandruBOLCU, Claudia Alina IOVAN 2016, 'A STUDY REGARDING THE DAMPING CAPACITY OF COMPOSITE BARS REINFORCED WITH FIBER GLASSAND THE MATRIX MADE WITH AMBRESIT', Fiabilitate şi Durabilitatehttp://www.utgjiu.ro/rev_mec/mecanica/pdf/2016-01.Supliment/20_Cosmin%20Mihai%20MIRI%C5%A2OIU,%20Cristian%20Oliviu%20BURADA,%20Marius%20Marinel%20ST%C4%82NESCU,%20Alexandru%20BOLCU,%20%20Claudia%20Alina%20IOVAN%20-%20A%20STUDY%20REGARDING%20THE%20DAMPING%20CAPACITY%20OF%20COMPOSITE%20BARS%20REINFORCED%20WITH%20FIBER%20GLASS%20AND%20THE....pdf. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
This paper presents two eigenfrequency-based damage diagnosis methods in a cantilever beam.
Chong Yang, Zhixu Zhang, Shaoning Nong, Changchun Zhu 2016, 'Analytical and experimental investigation on eigenfrequency-based damage diagnosisof cantilever beam', Journal of Vibroengineeringhttps://www.jvejournals.com/article/16797. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
From the developed pressure model, the eigenfrequency and damping were estimated.
Einar Agnalt, Petter Østby, Bjørn W. Solemslie, Ole G. Dahlhaug 2018, 'Experimental Study of a Low-Specific Speed Francis Model Runner during Resonance',Shock and Vibrationhttp://dx.doi.org/10.1155/2018/5796875. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
To avoid this problem, the fundamental eigenfrequency, an eigenfrequency of higher order, should be maximized.
Arsalan Alavi, Reza Rahgozar, Peyman Torkzadeh, Mohamad Ali Hajabasi 2017, 'Optimal design of high-rise buildings with respect to fundamental eigenfrequency',International Journal of Advanced Structural Engineeringhttp://link.springer.com/article/10.1007/s40091-017-0172-y. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
The valves also have a positive influence on an increasing of system eigenfrequency.
Vašina Martin, Hružík Lumír, Bureček Adam, Sikora Roman 2015, 'Dynamical behaviour of three-way throttle valve with pressure gradient stabilization',EPJ Web of Conferenceshttp://dx.doi.org/10.1051/epjconf/20159202104. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
In the case of composite rotors, this can lead to catastrophic failure if an eigenfrequency coincides with the rotational speed.
Angelos Filippatos, Maik Gude 2018, 'Influence of Gradual Damage on the Structural Dynamic Behaviour of Composite Rotors:Experimental Investigations', Materialshttps://www.mdpi.com/1996-1944/11/12/2421. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)
For every undamped eigenvalue exists its equivalent eigenfrequency and damping factor that can be used for further numerical analysis.
U. Miller, S. Bograd, A. Schmidt, L. Gaul 2010, 'Eigenpath Following for Systems with Symmetric Complex-Valued Stiffness Matrices',Shock and Vibrationhttp://dx.doi.org/10.3233/SAV-2010-0535. Retrieved from DOAJ CC BY 4.0 (https://creativecommons.org/licenses/by-sa/4.0/legalcode)