Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Dynamics of some vibro-impacting systems with amplitude constraints
Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mechanics of Solid Materials.ORCID iD: 0000-0001-6016-6342
1995 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis concerns the dynamics of some vibro-impacting systems with fixed or moving amplitude constraints. It is based on and includes five papers, marked A to E. Simple models of three different vibro-impacting systems with applications in the fields of impact hammers, granular flow and disk brakes in vehicles are analysed. A 2-DOF (two-degree-of-freedom) model of a threshold-limited impact hammer is studied (Paper A). The stability of a class of periodic motions is analysed. For some parameter values these periodic motions are found to be qualitatively similar to the ones observed for a corresponding 1-DOF system. At other parameter combinations, however, new kinds of periodic or chaotic motions can be observed. For low damping, phenomena resembling antiresonance for linear systems can also be observed. Granular shear flows show a transitional behaviour in the rapid flow regime as the shear speed or the concentration of the grains is varied. The motion can, for example, change from smooth and orderly to erratic and turbulent. Some aspects of this transitional behaviour in granular shear flow are studied numerically, analytically and experimentally (Papers B, C and D). Simple vibro-impacting models are suggested to get some analytical insight into the dynamics of shear layers. Results from a 1-DOF model show that for high forcing frequencies, which correspond to high shear speeds, periodic as well as chaotic motions can exist, whereas, for low forcing frequencies the vibrations are completely damped out to a stationary state (Paper B). Stability of this stationary state is studied analytically (Paper C), and experimentally (Paper D), where the motions of granular particles in a transparent shear cell are followed by using video techniques. For low shear speeds a single shear layer adjacent to the bottom boundary of the shear cell is observed. As the shear speed is increased, a transition to a random like state involving many layers is found to occur. In order to understand the phenomenon of squeal in disk brakes, a 3-DOF model is suggested to simulate the dynamics of a brake pad. The region of contact between the brake pad and the disk is described by using a coefficient of friction and distributed stiffness. The brake pad is allowed to have adjustable support locations and possibilities of impacts with its surroundings. The equilibrium state of the pad is determined by using a static analysis. The assumption is that the instability of this stationary state is a possible explanation of squeal, therefore, the stability is analysed in detail. Examples of different kinds of pad motions are presented. A rich variety of motions are found to exist including periodic, seemingly chaotic, stationary behaviour in slip, vibrations with full contact with the disk, stick-slip and impacts.

Place, publisher, year, edition, pages
Luleå: Luleå tekniska universitet, 1995. , 24 p.
Series
Doctoral thesis / Luleå University of Technologyy… → 31 dec 1996, ISSN 0348-8373 ; 163
National Category
Applied Mechanics Other Mechanical Engineering
Research subject
Solid Mechanics; Computer Aided Design
Identifiers
URN: urn:nbn:se:ltu:diva-16841Local ID: 0403d1f0-f428-11db-ac9f-000ea68e967bOAI: oai:DiVA.org:ltu-16841DiVA: diva2:989828
Note
Godkänd; 1995; 20070426 (ysko)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2017-11-24Bibliographically approved

Open Access in DiVA

fulltext(53898 kB)43 downloads
File information
File name FULLTEXT01.pdfFile size 53898 kBChecksum SHA-512
144b10846183e905dd38fec6de61108d1e5dbe3512bd426679249e5b50e9010c584379df7c311a22ee1ebf15f446e966d894a4492e2295635eef0c1bdd4d90f9
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Aidanpää, Jan-Olov
By organisation
Mechanics of Solid Materials
Applied MechanicsOther Mechanical Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 43 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 56 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf