Volume 5, Issue 8 (September 2008)

    Computer Simulation of Consecutive Ski Turns

    (Received 10 August 2007; accepted 9 July 2008)

    Published Online: 2008

    CODEN: JAIOAD

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    Abstract

    A computer model was developed to simulate consecutive ski turns. The model consists of a segment model for two skis and a single body for the skier. It was implemented in the multibody simulation software LMS Virtual.Lab. The interaction of ski and snow leads to a normal and a shearing force. For the normal force a hypoplastic relation between force and penetration depth was used. Hypoplasticity considers the effect that compacted snow is inelastic and deformations remain. For the shearing force orthogonal metal cutting theory was applied. During turns the skier has to keep balance. He leans inward to compensate centrifugal force. Neglecting angulation the complement of the inward lean angle is the mean value of the edge angles of the left and the right ski. With a suitable choice of the edge angles the skier kept the balance. Using this model the trajectory of the skier was simulated over four and a half turns. The first turn was rather carved, but in the last turn strong skidding was present. Due to increasing speed the centrifugal force considerably exceeded the shearing strength of snow. The hypoplastic force-penetration relation led to a reasonable penetration depth, which is a crucial factor for the shearing force. Based on this reference simulation the influence of edge angle and forward/backward lean was assessed by performing parameter studies. An increased edge angle caused smaller turn radii. Surprisingly, forward lean caused larger and backward lean smaller turn radii. This phenomenon could be explained by the turn moment of the skier. Both effects were more dominant when the skis skidded.


    Author Information:

    Mössner, Martin
    Research Assistent, University of Innsbruck, Fürstenweg,

    Heinrich, Dieter
    Research Assistent, University of Innsbruck, Fürstenweg,

    Kaps, Peter
    Professor, University of Innsbruck, Technikerstr.,

    Schretter, Herwig
    Director of Research and Development, HTM Tyrolia,

    Nachbauer, Werner
    Professor, University of Innsbruck,


    Stock #: JAI101387

    ISSN: 1546-962X

    DOI: 10.1520/JAI101387

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    Author
    Title Computer Simulation of Consecutive Ski Turns
    Symposium 17th Symposium on Skiing Trauma and Safety, 2007-05-19
    Committee F27