Department of Sport Science, University of Innsbruck, Innsbruck, Austria.
Scand J Med Sci Sports. 2010 Jun;20(3):485-92. doi: 10.1111/j.1600-0838.2009.00956.x. Epub 2009 Jun 23.
The macroscopic contact area between ski and snow and the contact pressure are crucial influencing factors for carved turns in Alpine skiing. In the present paper, a simulation model is developed to quantify these factors. The ski is modelled as an Euler-Bernoulli beam with variable cross section, camber, bending and torsional stiffness using measured data from skis. The reaction forces of the snow are decomposed in penetration and shear forces. For the penetration forces a hypoplastic constitutive law is applied incorporating elastic and plastic deformation of the snow at the contact area. For the shear forces metal cutting theory is used. Ski deformation, contact area and contact pressure are computed based on quasi-static equilibrium between forces exerted by the skier and snow reaction forces. Parameter studies are performed to investigate the influence of edging and distributing the load between the inner and outer ski. Higher edging angles as well as loading both skis affected the contact pressure positively by increasing the resistance against shearing. The results of our study agree well with measurement data taken from literature. Based on the results, the importance of actions of the skier during carved turns is concluded.
在高山滑雪中,雪板和雪之间的宏观接触面积和接触压力是至关重要的影响因素。本文建立了一个仿真模型来量化这些因素。雪板被建模为具有变截面、拱度、弯曲和扭转刚度的欧拉-伯努利梁,使用从雪板上测量的数据。雪的反作用力分解为穿透和剪切力。对于穿透力,应用了包含接触面积处雪的弹性和塑性变形的亚塑性本构定律。对于剪切力,使用了金属切削理论。基于滑雪者施加的力和雪的反作用力之间的准静态平衡,计算了雪板变形、接触面积和接触压力。进行了参数研究,以研究边缘和在内外雪板之间分配负载的影响。较高的边缘角度以及同时使用两个雪板通过增加抗剪切阻力,对接触压力产生了积极的影响。我们的研究结果与文献中的测量数据吻合较好。基于这些结果,得出了在刻滑转弯过程中滑雪者动作的重要性。