雪氷
Online ISSN : 1883-6267
Print ISSN : 0373-1006
31 巻, 5 号
選択された号の論文の6件中1~6を表示しています
  • 棚橋 良次
    1969 年 31 巻 5 号 p. 115-121
    発行日: 1969/09/30
    公開日: 2009/07/23
    ジャーナル フリー
    A well trained ski racer may be able to find instinctively what ski is the best. In the study of ski, it is necessa y to analyze scientifically the correlation between racer's feeling on the sliding ability and mechanical structure of ski. Single wood plate, phywood, alminium plate, steeledge, and synthet c resins such as FRP (Fiber Rienforced Plastic, ), polyethlene, ABS (Acrylnytril Butadiene Styrene), and phenolhave been used as the suitable materials for making skis. Structure of ski shoudl be designed taking into account the following requirements : the arch of ski should be maintained definitely for wide variation of temperature, the weight of ski has to be within a given range, the mechani cal strength of individual materials must not yield against internal stresses occuring during sliding, the structure and assembling of ski must bconvenient and simple for its manufacturing.
    When a static load is applied on a si, the pressure acting on the snow surface must be the same as the reactive force excerted from the snow surface. The reactive force (ξ) per unit length of ski may be given by
    f (ξ) =-d2/dξ2 [EI (ξ) d2/dξ2 {g (ξ) -g0 (ξ)}]
    where EI (ξ) is the bending stiffness ata a vigen point ξ, g (ξ) and g (ξ) are curve of ski arch and undulation of snow surface, respectively. The origin of (ξ) is taken at the center of ski (see Fig. 3). As seen in this equation, the reactive force depends on bending sti ffness, arch curve of ski and undulation of snow surface. This equation, however, may not be applicable for ski sliding down with high speedona slope. A combination of ski and racer is con sidered to be a kind of oscillation system. When the proper frequency od of this oscillation system coincides with the frequency of vibration caused by undulation of snow surface and speed of sliding ski, a resonance takes place in this oscillation system including racer. Therefore, the ski racer sliding down on the lope may feel strong vibration at snow surface. This vibrational energy should be absorbed by internal friction of ski. As the proper vibrational frequency of ski depends on EI and Weight of ski, studies of the distribution of these physical quantities along sliding surface must be very important.
  • 伊勢 俊正, 石井 邦男
    1969 年 31 巻 5 号 p. 124-125
    発行日: 1969/09/30
    公開日: 2009/07/23
    ジャーナル フリー
  • 小林 禎作
    1969 年 31 巻 5 号 p. 126-128
    発行日: 1969/09/30
    公開日: 2009/07/23
    ジャーナル フリー
  • 若浜 五郎
    1969 年 31 巻 5 号 p. 129-135
    発行日: 1969/09/30
    公開日: 2009/07/23
    ジャーナル フリー
  • 高橋 毅
    1969 年 31 巻 5 号 p. 136-142
    発行日: 1969/09/30
    公開日: 2009/07/23
    ジャーナル フリー
  • 1969 年 31 巻 5 号 p. 144
    発行日: 1969年
    公開日: 2009/07/23
    ジャーナル フリー
feedback
Top