论文标题

切换浅拱的动力学

Switching Dynamics of Shallow Arches

论文作者

Maharana, Priyabrata, Ananthasuresh, G. K.

论文摘要

本文提出了一种分析方法,可以预测非线性浅拱的延迟开关动力学,同时从一个状态转到另一个状态,以用于不同的加载情况。我们研究弹性弓对静态负载和时间依赖性负载进行研究。特别是,我们考虑了一个与时间相关的负载,该负载随着时间的恒定速率而随时间线性演变。在这两种情况下,我们都观察到当负载超过静态开关负载时,开关都不会突然发生,而是动态的时间尺度大大减慢。因此,切换会延迟。对于时间无关的负载,随着施加的负载接近静态开关负载,此延迟会增加。而对于时间依赖的负载,该延迟与所施加的载荷的速率成正比。除了加载参数外,延迟切换时间还取决于静态切换点的力 - 位置函数的局部曲率和拱材料的阻尼系数。由于静态开关载荷下能量曲线的平坦度,发生延迟开关。因此,我们将拱形切换点附近的拱门线性化,并获得降低的非线性普通微分方程,以研究拱门的开关动力学。减少的方程式使我们能够为延迟切换时间的分析表达式得出分析表达式。我们进一步将派生的分析结果与数值解决方案进行了比较,并观察到了它们之间的良好一致性。最后,派生的分析公式可用于设计用于自下载的糖尿病患者动态鞋类的拱门。

This paper presents an analytical method to predict the delayed switching dynamics of nonlinear shallow arches while switching from one state to another state for different loading cases. We study an elastic arch subject to static loading and time-dependent loading separately. In particular, we consider a time-dependent loading that evolves linearly with time at a constant rate. In both cases, we observed that the switching does not occur abruptly when the load exceeds the static switching load, rather the time scale of the dynamics drastically slows down; hence there is a delay in switching. For time-independent loading, this delay increases as the applied load approach the static switching load. Whereas for a time-dependent loading, the delay is proportional to the rate of the applied load. Other than the loading parameters, the delay switching time also depends on the local curvature of the force-displacement function at the static switching point and the damping coefficient of the arch material. The delay switching occurs due to the flatness of the energy curve at static switching load. Therefore, we linearize the arch near the static switching point and get a reduced nonlinear ordinary differential equation to study the switching dynamics of the arch. This reduced equation allows us to derive analytical expressions for the delay switching time of the. We further compare the derived analytical results with the numerical solutions and observed a good agreement between them. Finally, the derived analytical formulae can be used to design arches for self-offloading dynamic footwear for diabetics.

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