Mössner M, Heinrich D, Schindelwig K, Kaps P, Schretter H, Nachbauer W
Department of Sport Science, University of Innsbruck, Innsbruck, Austria.
Scand J Med Sci Sports. 2014 Jun;24(3):577-85. doi: 10.1111/sms.12035. Epub 2013 Jan 7.
A ski-snow interaction model is presented. The force between ski and snow is decomposed into a penetration force normal to the snow surface, a shear force parallel to it, and friction. The purpose of this study was to investigate the benefits of a hypoplastic vs an elastic contact for penetration in the simulation of skiing turns. To reduce the number of influencing factors, a sledge equipped with skis was considered. A forward dynamic simulation model for the sledge was implemented. For the evaluation of both contact models, the deviation between simulated trajectories and experimental track data was computed for turns of 67 and 42 m. Maximum deviations for these turns were 0.44 and 0.14 m for the hypoplastic contact, and 0.6 and 7.5 m for the elastic contact, respectively. In the hypoplastic contact, the penetration depth of the ski's afterbody maintained nearly the same value as the part under maximum load, whereas it decreased in the elastic contact. Because the shear force is proportional to the penetration depth, the hypoplastic contact resulted in a higher shearing resistance. By replacing the sledge with a skier model, one may investigate more complex skier actions, skiing performance, or accident-prone skiing maneuvers.
本文提出了一种滑雪-雪地相互作用模型。滑雪板与雪地之间的力可分解为垂直于雪面的穿透力、平行于雪面的剪切力以及摩擦力。本研究的目的是探讨在模拟滑雪转弯时，与弹性接触相比，亚塑性接触在穿透方面的优势。为了减少影响因素的数量，考虑了一个配备滑雪板的雪橇。实现了雪橇的正向动力学仿真模型。为了评估这两种接触模型，针对67米和42米的转弯计算了模拟轨迹与实验轨迹数据之间的偏差。对于这些转弯，亚塑性接触的最大偏差分别为0.44米和0.14米，弹性接触的最大偏差分别为0.6米和7.5米。在亚塑性接触中，滑雪板后体的穿透深度与最大载荷作用部分的穿透深度几乎保持相同的值，而在弹性接触中则会减小。由于剪切力与穿透深度成正比，亚塑性接触产生了更高的抗剪强度。通过用滑雪者模型取代雪橇，可以研究更复杂的滑雪者动作、滑雪性能或易发生事故的滑雪动作。
