共查询到18条相似文献，搜索用时 375 毫秒
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对低重心男子标枪主要飞行初始条件组合的研究 总被引：3，自引：0，他引：3
本文使用计算机模拟的方法,并根据新规则研究了男子标枪飞行的最佳初始条件组合。根据风洞实验的气动力和力矩分析了新、旧标枪的差异。用等高线图分析了出手角度、初始攻角和初始俯仰角速度之间的关系,并讨论了各初始条件的敏感性。为标枪运动员提供了有实际意义的最佳初始条件组合。 相似文献
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本文对国内外部分优秀男子标枪运动员最后出手瞬间的几个角度进行比较分析，发现我国男子标枪运动员出手参数的部分角度不合理，左膝角度相对偏小缓冲角度偏大、右膝角偏大缓冲角度过大、标枪出手角度合理但姿态角、攻角、晃动角偏大。 相似文献
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我们知道田径运动成绩决定于器械出手初速、出手角度、出手高度、自然条件等.通常人们比较重视出手初速。无可否认出手初速是最重要的。然而,在比赛中,运动员投掷器械出手初速的能力都比较相当的情况下,出手角度的重要性就突出出来了。尤其是标枪这类形状及飞行状态比较特别的器械,合理的投掷出手角度更为重要,原因是它直接关系到标枪在飞行中是否合理利用了空气动力。国外专家研究报告,投掷标枪成绩和投掷角的相关 相似文献
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通过对我国优秀女子标枪运动员投枪出手速度的效果测度灰色关联分析，揭示其有关因素对标枪出手速度所起的作用及地位。结果表明：影响标枪出手速度的首要因素是标枪离手时的左膝角，说明左腿迅速而充分的蹬伸对出手速度起着重要的影响作用。 相似文献
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关于男子低重心标枪出手条件的分析 总被引：2，自引：0，他引：2
在标枪风洞测力实验基础上,建立标枪飞行数理模型进行计算机优化,得到了有规律的结论,结合投掷实践分析了标枪出手适宜条件。出手初速在25m/s～30m/s的范围内,最佳出手条件是:投掷角为40°,迎角为-11°。就投掷成绩而言,负攻角比零攻角好,零攻角又比正攻角好。低重心标枪俯仰力矩值比旧标枪大,低重心标枪出手条件不好,投掷成绩下降幅度比旧标枪大。一般情况下投掷角不能小,攻角绝对值不能大,这样相应成绩更好些。投掷标枪不能沿纵轴用力,也不可能沿纵轴用力。标枪以不为零的攻角出手是获得空气动力效率的充分必要条件。 相似文献
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考虑空气阻力时标枪最佳出手角度研究 总被引：1，自引：0，他引：1
对考虑空气阻力时标枪的最佳出手角进行计算机仿真研究。通过刚体理论,推导了考虑空气阻力时标枪的动力学方程组,并在不同出手参数组合的情况下对标枪的出手角进行计算和分析。采用文献中的有关标枪的几何和物理参数,使用Mathematica数学软件进行方程的推导和数值计算。通过计算,得到标枪的初始攻角和俯仰角速度对出手角度选择的影响较显著。若无初始俯仰角速度时,最好的出手角度范围为37°~43°,其中42°最佳;最好的出手范围为39°~44°,其中43°最佳;攻角的适宜值为-9°~0°,初始俯仰角速度的适宜值为-12°/s~-6°/s。 相似文献
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Thomas Reilly 《Journal of sports sciences》2013,31(1):1-2
In this paper, the scientific literature and that on the sports sciences relevant to javelin throwing is critically reviewed. This is particularly timely because of the change in the specification of the javelin for the men's event, which was introduced by the IAAF in 1986. A full discussion of the aerodynamics of the javelin is presented with due consideration of the change in pitching moment characteristics that the rules change had brought about. The uses and limitations of current computer programs for simulating javelin flight, in order to estimate optimal release parameters, are profiled. Consideration is also given to the effects of wind velocity, air density, javelin weight and the flutter and spin of the javelin on its flight. The review further considers the optimization of release parameters, drawing upon computer simulations and field‐based data. The effects of release speed, release height, release angle, release angle of attack and release pitch rate are assessed. The javelin throwing technique is discussed in relation to cinematographically derived data, including an evaluation of experimental procedures. The importance to successful performance of the grip, the run‐up and transition phases, the cross over and delivery strides are each reviewed. Finally, some prognoses as to the direction of future research into this complex throwing skill are offered. 相似文献
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In this paper, the scientific literature and that on the sports sciences relevant to javelin throwing is critically reviewed. This is particularly timely because of the change in the specification of the javelin for the men's event, which was introduced by the IAAF in 1986. A full discussion of the aerodynamics of the javelin is presented with due consideration of the change in pitching moment characteristics that the rules change had brought about. The uses and limitations of current computer programs for simulating javelin flight, in order to estimate optimal release parameters, are profiled. Consideration is also given to the effects of wind velocity, air density, javelin weight and the flutter and spin of the javelin on its flight. The review further considers the optimization of release parameters, drawing upon computer simulations and field-based data. The effects of release speed, release height, release angle, release angle of attack and release pitch rate are assessed. The javelin throwing technique is discussed in relation to cinematographically derived data, including an evaluation of experimental procedures. The importance to successful performance of the grip, the run-up and transition phases, the cross over and delivery strides are each reviewed. Finally, some prognoses as to the direction of future research into this complex throwing skill are offered. 相似文献
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在调查访问的基础上，运用文献资料法获取研究必须的各类参数和数据，用计算机模拟的方法，建立标枪运动的微分方程，通过定量、定性分析对决定标枪飞行远度的重要因素进行研究，使运动员和教练员可以全面、准确了解各因素对成绩影响以及它们之间的相互关系，从而对运动训练起到指导作用。 相似文献
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本文通过对我国优秀标枪运动员和世界优秀标枪运动员投掷步技术的分析与对比,结果发现：我国男子标枪运动员投掷步第1、2步躯干后倾角过大,第2～3步躯干后倾角变化幅度相对较小,以至于交叉步的动作速度及幅度受到影响;女子标枪运动员交叉步下肢前移幅度过小,影响躯干相关肌群收缩;我国男女运动员投掷步第4步都存在躯干后倾角下降较大,左膝弯屈角较小,左侧支撑无力的共性特征。 相似文献
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谈现代标枪投掷技术的特点与发展趋势 总被引：1，自引：1，他引：0
井红丽 《哈尔滨体育学院学报》2006,24(4)
能力是基础,技术是关键,这是现代标枪的投掷特点和发展趋势。因此在投掷过程中首先要了解标枪在空中的运行轨迹并结合标枪的特点采取相适应的出手角和冲击角,才能发挥运动员身体最大潜能获得良好运动成绩。 相似文献
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我国优秀女子标枪运动员投掷步技术的运动学研究 总被引：3，自引：1，他引：2
对十运会田径比赛女子掷标枪决赛前8名运动员的投掷步技术进行解析研究。结果表明,我国优秀女子标枪运动员助跑速度快,但速度利用率却不高;投掷步时短,步频快,不能为最后的用力做好充分的准备;投掷各步躯干后倾角变化小,对标枪施力不够;左脚落地时膝角缓冲过大,制动效果差。同时,投掷成绩与最后交叉步后身体重心水平速度在一定程度上呈正相关。 相似文献
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This paper describes the use of Pareto-optimal solutions for the screw kick in rugby. We attempted to optimise the initial
conditions for a screw kick. The optimisation was carried out using an elitist non-dominated sorting genetic algorithm. Distance
achieved in flight is considered as an objective function, as well as the lateral deviation between the ball and the touchline,
or the flight time. Six initial conditions were defined as control parameters: the magnitude of the velocity vector, the flight
path angle, the azimuth angle, the spin rate, the pitch angle and the yaw angle. The results are summarised as follows: it
is impossible for both objective functions to be satisfied simultaneously, although the greatest distance achieved in flight
and the smallest value of the lateral deviation between the ball and the touchline, or the least flight time, is the ideal
situation. This kind of conflicting solution is called a ‘Pareto-optimal solution’. The optimal kick in Pareto-optimal solutions
made by the leg nearest the touchline produces a greater flight distance than the optimal kick in Pareto-optimal solutions
made using the leg furthest from the touchline. The initial pitch angle, which is the angle between the longitudinal axis
of the ball and the horizontal plane, should be comparable to or slightly greater than the initial flight path angle in order
to satisfy the Pareto-optimal solutions. 相似文献