Primož Ogrinec (Author), Janko Slavič (Author), Martin Česnik (Author), Miha Boltežar (Author)

Abstract

Three types of loads are typical in vibration fatigue: random, harmonic and impact. In an application, any combination of these loads is possible. In vibration fatigue the random loads can be investigated by using the frequency-response function of the structure. While the theoretical relationship between the frequency-response function and the impact-response function is clear (they form the Fourier pair), the time/frequency relationship of vibration-fatigue damage has not yet been investigated in detail. The focus of this research is a theoretical study of the time- and frequency-domain damage of a single-degree-of-freedom dynamic system under well-separated half-sine impulse excitation. The introduced theoretical relationship between the time- and frequency-domain (Narrow-band and Tovo-Benasciutti method) damage showed that the significantly different results are related to the underlying dynamic properties (e.g., natural frequency and damping) of a flexible system. Based on the introduced relationship, the frequency-domain damage estimation is corrected for a reliable damage estimation. In addition, an experimental test case is presented. The introduced theoretical relationship opens up new possibilities to investigate the impact excitation in the frequency domain and provides the necessary theoretical background for applications when the impacts are not well separated and start to overlap, resulting in the broadband excitation observed in clearance contacts.

Keywords

vibration fatigue;random loads;spectral methods;fatigue life;stationary loading;non-stationary loading;non-Gaussian loading;

Data

Language: English
Year of publishing:
Typology: 1.01 - Original Scientific Article
Organization: UL FS - Faculty of Mechanical Engineering
UDC: 534.12:539.43(045)
COBISS: 16539419 Link will open in a new window
ISSN: 0142-1123
Views: 670
Downloads: 295
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Metadata: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Other data

Secondary language: Slovenian
Secondary title: Vibracijska poškodovanost v časovni in frekvenčni domeni za primer pol-sinusnih impulznih obremenitev
Secondary abstract: V vibracijskem utrujanju se srečujemo s tremi tipi obremenitev: naključnimi, harmonskimi in impulznimi. V praksi pa so možne kombinacije teh obremenitev. Naključne obremenitve obravnavamo v frekvenčni domeni, z upoštevanjem strukturne dinamike obravnavane strukture. Medtem ko so teoretične relacije med frekvenčnimi prenosnimi funkcijami in impulzno- prenosnimi funkcijami dobro znane, razmerje med napovedjo poškodbe v časovni in frekvenčni domeni še ni bilo podrobno raziskano. V tej raziskavi je predstavljena teoretična študija napovedi poškodbe tako v časovni, kot tudi v frekvenčni domeni, za sistem z eno prostostno stopnjo, ki je obremenjen z polsinusnimi impulzi. Iz prikazanih rezultatov razmerij med časovno (padavinska) in frekvenčnima števnima metodama(ozko-spektralna, Tovo-Bennasciutti) je razvidno, da so napovedi dobe trajanja z različnimi metodami neskladne. Z predstavljenim analitičnim razmerjem je mogoče ustrezno korigirati obravnavani frekvenčni metodi. V delu je predstavljeno tudi eksperimentalno delo, ki potrjuje teoretične zaključke. Opisan analitični postopek odpira nove možnosti raziskave impulznih obremenitev v frekvenčni domeni in predstavlja potrebno teoretično ozadje za obremenitvene primere kjer impulzi niso dobro ločeni in se prekrivajo, kar rezultira v široko-spektralnem vzbujanju.
Secondary keywords: vibracijsko utrujanje;naključne obremenitve;spektralne števne metode;napoved dobe trajanja;stacionarne obremenitve;nestacionarne obremenitve;ne-Gaussovo vzbujanje;
Type (COBISS): Article
Embargo end date (OpenAIRE): 2021-02-23
Pages: str. 308-317
Issue: ǂVol. ǂ123
Chronology: Jun. 2019
DOI: 10.1016/j.ijfatigue.2019.02.031
ID: 11085285