Change search
Refine search result
1 - 16 of 16
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • 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
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Andersson, Angelica
    et al.
    Luleå tekniska universitet.
    Runnemalm, Anna
    Luleå tekniska universitet.
    Sjödahl, Mikael
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Digital speckle pattern interferometry: fringe retrieval for large in-plane deformations with digital speckle photography1999In: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 38, no 25, p. 5408-5412Article in journal (Refereed)
    Abstract [en]

    The compensation of large in-plane motions in digital speckle-pattern interferometry (DSPI) with the use of digital speckle photography (DSP) is demonstrated. Ordinary recordings of DSPI are recombined and analyzed with DSP. The DSP result is used to compensate for the bulk speckle motion prior to calculation of the phase map. This results in a high fringe contrast even for deformations of several speckle diameters. In addition, for the case of an in-plane deformation, it is shown that the absolute phase change in each pixel may be unwrapped by use of the DSP result as an initial guess. The principles of this method and experiments showing the in-plane rotation of a plate and the encounter of two rounded plates are presented

  • 2.
    Bergström, Per
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mathematical Science.
    Fergusson, Michael
    Xtura AB, Kungsbacka.
    Folkesson, Patrik
    Xtura AB, Kungsbacka.
    Runnemalm, Anna
    University West, Department of Engineering Sciences, Trollhättan.
    Ottosson, Mattias
    University West, Department of Engineering Sciences, Trollhättan.
    Andersson, Alf
    Chalmers University of Technology, Department of Product and Production Development.
    Sjödahl, Mikael
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Automatic in-line inspection of shape based on photogrammetry2016In: SPS16, Lund: SPS16 , 2016, , p. 9Conference paper (Refereed)
    Abstract [en]

    We are describing a fully automatic in-line shape inspection system for controlling the shape of moving objects on a conveyor belt. The shapes of the objects are measured using a full-field optical shape measurement method based on photogrammetry. The photogrammetry system consists of four cameras, a flash, and a triggering device. When an object to be measured arrives at a given position relative to the system, the flash and cameras are synchronously triggered to capture images of the moving object. From the captured images a point-cloud representing the measured shape is created. The point-cloud is then aligned to a CAD-model, which defines the nominal shape of the measured object, using a best-fit method and a feature-based alignment method. Deviations between the point-cloud and the CAD-model are computed giving the output of the inspection process. The computational time to create a point-cloud from the captured images is about 30 seconds and the computational time for the comparison with the CAD-model is about ten milliseconds. We report on recent progress with the shape inspection system.

  • 3. Jansson, E
    et al.
    Moral, Alonso
    Frydén, L.
    Niewczyk, B.
    Molin, Nils-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Runnemalm, Anna
    Saldner, Henrik
    Wåhlin, Anders
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    On the acoustical function of the violin1997In: 25. Congresso nazionale : Perugia, 21-23 maggio 1997 : atti / Associazione italiana di acustica, 1997Conference paper (Refereed)
  • 4.
    Rossing, Thomas D.
    et al.
    Northern Illinois University.
    Molin, Nils-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Runnemalm, Anna
    Luleå tekniska universitet.
    Modal analysis of violin bodies viewed as three-dimensional structures2003In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 114, no 4, p. 2438-Article in journal (Refereed)
    Abstract [en]

    Modal analyses of violins show several strong modes in the low frequency range. Holographic interferograms suggest that four strong modes can be interpreted as doublets having two and three nodal planes that intersect a cylinder with a roughly elliptical cross section at the bridge [A. Runnemalm, N.-E. Molin, and E. Jansson, J. Acoust. Soc. Am. 107, 3452-3459 (2000); M. Roberts and T. D. Rossing, Catgut Acoust. Soc. J. 3, 9-15 (1998)]. This is especially clear when the instrument is viewed simultaneously from three sides using mirrors, and the holographic system is made sensitive to in-plane motion as well. These doublets are not unlike those observed in cylindrical vibrators such as bells, and they remind us that a violin is a 3-dimensional object

  • 5. Runnemalm, Anna
    Effects of material choice and tooling methods on structural modes of open organ pipes1997In: ISMA'97, Institute of Acoustics , 1997, p. 345-352Conference paper (Refereed)
    Abstract [en]

    How are wall vibrations of organ pipes influenced by material choice and tooling methods ? Six groups of three equally made diapason organ pipes (tuned to C4 at 260 Hz) fabricated out of two different alloys and with three tooling methods are investigated. All experiments are performed with the pipes mounted in an experimental organ. Results from the following experiments are compared: Modes of vibration for external sinusoidal excitation of the walls, so called free structural eigenmodes, are measured using TV holography, a non contact, optical, full field measuring method. These measurements are performed both before and after voicing of the pipes. The pipes are externally excited, sinusoidal, at the fundamental frequency and five higher harmonics (n*260 Hz where n = 1, 2, ..., 6) of the blown pipe. Forced structural modes of vibration at those frequencies are measured, again using TV holography. Structural modes of vibration of the blown pipes are measured. This time shearography is used, another optical non contact measuring method.The results show that structural vibrations are affected by the choice of material and tooling; a pipe with higher tin contents have higher eigenfrequencies. It is also shown that the voicing process selects certain modes of vibration in the pipes.

  • 6.
    Runnemalm, Anna
    Luleå tekniska universitet.
    Sound and vibrations in structures with air enclosures1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Vibrations in thin shell structures and sound fields in enclosures are investigated as well as the interaction between such structures and the enclosed sound field. Optical, non-contacting methods as TV holography, shearography and laser scanning vibrometry are used to investigate vibrations of thin shell structures with air enclosures. The sound radiation from vibrating structures is also measured with more traditional sound intensity techniques. The techniques used are briefly presented and compared in this thesis. Structural vibrations in organ pipes made of different materials are investigated as well as the sound distribution from the pipes. Operating deflection shapes of a complete violin are investigated, and the effect of enclosed air on structural vibrations is measured on a violin model. Aerial standing waves inside three cavities are measured and visualised with an optical technique. The response of the shell structures due to aerial standing waves is also measured. From the investigations it is found that the enclosed air has a significant effect on, above all, the lowest eigenmodes. It is also shown that non-contacting measuring techniques have advantages in that they do not to disturb the measured object and in that they are field methods. In numerical comparisons to the measurements it is found that the enclosed air should be included in the numerical model to predict correct results. Two different finite element models of the enclosed air are tested.

  • 7.
    Runnemalm, Anna
    Luleå tekniska universitet.
    Standing waves in a rectangular sound box recorded by TV holography1999In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 224, no 4, p. 689-707Article in journal (Refereed)
    Abstract [en]

    A simple but informative whole-field method to visualize standing waves in air enclosures is presented. The integrated sound pressure field distribution of standing-wave patterns inside a rectangular, air-filled transparent box is measured using ordinary TV holography (also called ESPI or DSPI). The phase distribution of the sound pressure is measured by using the more complicated, phase-modulated TV holography technique. Standing waves in the box are excited by a loudspeaker. The structural vibration amplitude distribution of the walls of the same box (operational deflection shapes, ODSs) are measured at the same frequencies as the standing waves with the same optical technique. The pressure maps obtained and the corresponding structural ODSs are of great pedagogical value and can be used to verify numerical models, etc. Standing-wave patterns in non-rectangular enclosures, as the sound box of a guitar, illustrates the usefulness of the method.

  • 8.
    Runnemalm, Anna
    Luleå tekniska universitet.
    Vibrations and sound from structures with air enclosures1997Licentiate thesis, comprehensive summary (Other academic)
  • 9.
    Runnemalm, Anna
    et al.
    Luleå tekniska universitet.
    Fällström, Karl-Evert
    Varför låter en orgelpipa som den gör?1997In: Övertorneåprojektet: om dokumentationen av orgeln i Övertorneå och rekonstruktionen av 1684 års orgel i Tyska kyrkan, Piteå: Luleå tekniska universitet, 1997, p. 115-127Chapter in book (Other (popular science, discussion, etc.))
  • 10.
    Runnemalm, Anna
    et al.
    Luleå tekniska universitet.
    Johansson, Örjan
    Sound intensity measurements of an open organ pipe1997In: ISMA 97 conference / [ed] Arnold Myers, Institute of Acoustics , 1997Conference paper (Refereed)
    Abstract [en]

    What part of an open organ pipe emits most of the sound and what is the spatial sound distribution for the harmonic tones? The sound intensity from a blown open organ pipe, tuned to C4 at 260 Hz, is measured in an anechoic room using a 3D sound intensity probe. The measurements are performed both in the vertical and in the horizontal plane in front of the pipe. The two dimensional sound intensity vector field for different harmonic tones are studied. The study focuses on the active mean intensity field and the results point out the main sources of acoustic power and their contribution to the far field. Pipes made of different material and tooled in different ways are compared. Interference phenomena between sources are also visualised. First it can be noted that the top and the mouth are the main sound radiators compared to the walls. They are of about the same strength for the first four harmonics. For the fifth and sixth harmonics the top is the main sound radiator. For odd numbered harmonic tones the mouth and the top emit sound in phase and for even numbers, out of phase. The material choice and tooling method affect the sound spectra.

  • 11.
    Runnemalm, Anna
    et al.
    Luleå tekniska universitet.
    Molin, Nils-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Air cavity modes in sound boxes recorded by TV holography1999In: Joint meeting, 137th regular meeting of the Acoustical Society of America, 2nd convention of the European Acoustics Association: Forum Acusticum 99, integrating the 25th German Acoustics DAGA Conference : Technical University of Berlin, Berlin, Germany, 15 - 19 March 1999 ; [program with abstracts], Woodbury, NY: Acoustical Society of America (ASA), 1999Conference paper (Refereed)
  • 12.
    Runnemalm, Anna
    et al.
    Luleå tekniska universitet.
    Molin, Nils-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Operating deflection shapes of the plates and standing aerial waves in a violin and a guitar model2000In: Acustica, ISSN 0001-7884, Vol. 86, no 5, p. 883-890Article in journal (Refereed)
    Abstract [en]

    Phase modulated TV holography is used to measure sound pressure variations of standing waves of the air inside cavities of transparent models of a violin and a guitar. The accompanying motions, the Operating Deflection Shapes (ODSs) of the now white painted walls of the enclosures are measured using TV holography. Experimental measurements of the ODSs are compared to finite element calculations of the coupled air cavity and plate motion

  • 13.
    Runnemalm, Anna
    et al.
    Luleå tekniska universitet.
    Molin, Nils-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Jansson, Erik
    Kungliga tekniska högskolan, KTH.
    On operating deflection shapes of the violin body including in-plane motions2000In: Journal of the Acoustical Society of America, ISSN 0001-4966, E-ISSN 1520-8524, Vol. 107, no 6, p. 3452-3459Article in journal (Refereed)
    Abstract [en]

    Earlier investigations have assumed only "out-of-plane" vibrations of the plates of the violin. The violin body can, however, be described as a thin-walled, double-arched shell structure and as such it may very well elongate in one direction as it contracts in another. Therefore, at least two orthogonal vibration components have to be included to describe the vibrations. The operating deflection shapes (ODSs) of a good, professionally made and carefully selected violin were therefore measured in several directions by TV holography to determine both "in-plane" and out-of-plane vibration components of the ODSs. The observations were limited to the frequency range 400-600 Hz, as this interval includes two most-prominent resonance peaks of bridge mobility and sound radiation as well as a third poorly radiating resonance. These three peaks clearly showed orthogonal vibration components in the ODSs. The vibration behavior of the violin body, sectioned in the bridge plane, was interpreted as the vibrations of an "elliptical tube" with nodal diameters. The number of nodal diameters increases from two to three in the selected frequency range. The TV holography measurements were supported by electrodynamical point measurements of bridge mobility, of air volume resonances, and by reciprocity, of radiation properties. Furthermore, a fourth mode, the air mode, A1, is involved indirectly in the sound radiation via influence on the body vibrations.

  • 14.
    Runnemalm, Anna
    et al.
    Luleå tekniska universitet.
    Molin, Nils-Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Jansson, E.V.
    Kungliga tekniska högskolan, KTH.
    Operating deflection shapes and the function of the violin1998In: Årsrapport: Årsrapport, Stockholm: Department of Speech, Music and Hearing, Royal Institute of Technology , 1998, p. 5-17Chapter in book (Other academic)
  • 15.
    Runnemalm, Anna
    et al.
    Luleå tekniska universitet.
    Saldner, Henrik
    Luleå tekniska universitet.
    Fällström, Karl-Evert
    Material, structural modes and air modes of an open organ pipe1997Report (Other academic)
  • 16.
    Runnemalm, Anna
    et al.
    Luleå tekniska universitet.
    Zipser, Lothar
    Department of Electrical Engineering, University of Applied Technology Dresden.
    Franke, Heinz
    Department of Electrical Engineering, University of Applied Technology Dresden.
    Structural vibration modes of a blown open organ pipe1999In: Acta Acoustica united with Acustica, ISSN 1610-1928, E-ISSN 1861-9959, Vol. 85, no 6, p. 877-882Article in journal (Refereed)
    Abstract [en]

    How do the walls of an open organ pipe vibrate when blown? Two geometrically similar open organ pipes are made of different alloys and tooled in different ways. Using a scanning laser Doppler vibrometer the operational deflection shapes (forced modes of vibration) for the first three harmonic partials of the blown pipes are measured. The upper lip is further investigated for the five first harmonic partials. The results are compared and related to the sound intensity distribution from the pipes. This comparison shows that the vibration modes of the structure are dependent upon the material of the pipes. Both the amplitude and the shape of the vibration differ between the pipes. It is found that the vibration amplitude is low for the fifth harmonic partial. For this partial the sound intensity emitted from the mouth also is low.

1 - 16 of 16
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • 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