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Dynamics of Rolling Friction in Soft-rigid Interface

软-刚界面滚动摩擦动力学

基本信息

批准号：
1916840
负责人：
Michael Leamy
金额：
$ 41.13万
依托单位：
Georgia Tech Research Corporation
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2019
资助国家：
美国
起止时间：
2019-08-15 至 2024-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1916840&HistoricalAwards=false
关键词：
Dynamics Rolling Friction Soft rigid

项目摘要

This research project addresses the need for a comprehensive understanding of the nonlinear dynamics of soft rolling contact to enable prediction of instabilities arising from local frictional interference. The current state-of-knowledge regarding the modeling of soft contact dynamics is still based on a 300-year-old concept of a coefficient of friction, which was developed to represent global frictional behavior of hard rough surfaces. This concept ignores local stick-slip instabilities that represent an important source of excitation for any dynamic system involving friction. The effort will contribute to the understanding of dynamics of rolling friction in soft-rigid interfaces by abandoning the principles formulated by Amontons and Coulomb for rigid body mechanics, and by introducing the modern perception of soft adhesive contact behavior into dynamics analysis. Soft rolling motion is ubiquitous in countless engineering applications ranging from vehicle tires to power transmission in belt drives, to soft robotic grasping. If successful, the effort will significantly increase the current understanding of these systems, leading to analysis and design that will reduce energy losses, noise pollution, loss of accuracy, wear, etc. associated with dynamic effects. Successful completion of the research will also introduce an alternative way of addressing contact problems in flexible dynamics simulation, which will significantly expand the capabilities of the computational dynamics research community. The project includes outreach activities to increase participation of underrepresented groups in engineering through K-12 internship and training opportunities in the investigators' labs.This research will explore newly-uncovered nonlinear dynamics and instabilities associated with soft rolling contact, with the objective of posing new/incorporating appropriate first-principle models based on intermolecular (adhesive) and interatomic (viscous) interactions. Without employing the concept of a friction coefficient nor the assumption of local sliding, which are both long-held and in direct conflict with experimental observations, the approach will focus on introducing a coupling of the deterministic dynamic response of the rolling system to relative contact displacements associated with a local stochastic normal (adhesive) separation and out-of-contact tangential motion. From this conceptual context will emerge the observed nonlinear dynamics and global instabilities. Results from the predictive approach will be compared to elaborated experiments involving dynamic measurements of rolling friction, observation of contact area evolutions, and examination of deformations in the near-contact zone, while using materials having different adhesive and viscous properties.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该研究项目解决了对软滚动接触的非线性动力学的全面理解的需要，从而能够预测局部摩擦干扰引起的不稳定性。目前关于软接触动力学建模的知识状态仍然基于有300年历史的摩擦系数概念，该概念是为了表示硬粗糙表面的全局摩擦行为而开发的。这个概念忽略了局部粘滑不稳定性，这是任何涉及摩擦的动态系统的重要激励源。这一努力将有助于通过放弃Amontons和Coulomb为刚体力学制定的原则，并通过将柔性粘合剂接触行为的现代感知引入动力学分析来理解软硬界面中的滚动摩擦动力学。软滚动运动在无数工程应用中无处不在，从车辆轮胎到皮带传动中的动力传输，再到软机器人抓取。如果成功，这项工作将大大增加目前对这些系统的了解，从而导致分析和设计，减少与动态效应相关的能量损失，噪音污染，精度损失，磨损等。研究的成功完成还将引入一种解决柔性动力学模拟中接触问题的替代方法，这将大大扩展计算动力学研究界的能力。该项目包括通过K-12实习和在研究人员实验室的培训机会来增加代表性不足的群体在工程中的参与的外展活动。这项研究将探索新发现的非线性动力学和与软滚动接触相关的不稳定性，目的是提出新的/纳入适当的基于分子间（粘合剂）和原子间（粘性）相互作用的第一原理模型。没有采用的摩擦系数的概念，也没有假设的局部滑动，这是长期持有的，并与实验观察直接冲突，该方法将集中在引入一个耦合的滚动系统的确定性动态响应的相对接触位移与当地的随机正常（粘合剂）分离和接触外的切向运动。从这个概念的背景下，将出现观察到的非线性动力学和全球不稳定性。预测方法的结果将与详细的实验进行比较，这些实验包括滚动摩擦的动态测量、接触面积演变的观察以及近接触区变形的检查，该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查进行评估，被认为值得支持的搜索.