Dynamic interface analysis

这项正在进行的研究计划的目的是开发方法论和基于仿真的工具，用于调查在规定的确定性和伪随机运动环境中运行的动态系统的行为。注意力特别集中在两个代表性系统：直升机/船舶动态界面和人体姿势稳定性。在本赠款申请期间，计划实现三个短期目标。(1)直升机/船舶系统的计算模型将与海况天气模型和伪随机船舶运动生成方法一起被改进和集成到一个通用的蒙特卡罗模拟中，这样基于风险的概率方法可以用来发现与界面载荷谱有关的难以捉摸的细节。载荷谱将有效量化寿命周期界面载荷、超过各种设计峰值和疲劳载荷极限的概率，并允许平台运动和界面力之间的频域关联。(2)桨叶航行，即由于船舶运动和非定常空气动力学而在低转速下发生的叶片大挠度现象，将继续进行计算和实验研究，以发现各种条件如何影响叶片航行，以及使用主动控制的智能材料可以在多大程度上减弱这种现象。刚性段和连续梁建模方法都用于提供精确的计算效率的解决方案，非常适合于参数化研究。(3)姿态稳定性研究将继续发展人体运动基础上的关节动力学模型，确定模型复杂性与保真度之间的关系，并利用结果建立精确的运动诱导中断模型。从这些相互关联的项目推断将被考虑和推广，如果可能的话，在规定的运动界面问题的背景下。

The purpose of this on-going research program is to develop methodology and simulation-based tools for investigating the behaviour of dynamic systems operating in prescribed deterministic and pseudo-random motion environments. Attention is specifically focused on two representative systems: the helicopter/ship dynamic interface and human postural stability. Three short-term objectives are planned for the period covered by this grant application. (1) A computational model of a helicopter/ship system will be refined and integrated, along with a sea state weather model and pseudo-random ship motion generation approach, into a versatile Monte Carlo simulation such that risk-based probabilistic methodology can be used to discover elusive details relating to interface load spectra. The load spectra will effectively quantify life cycle interface loading, probability of exceeding various design peak and fatigue load limits, and allow frequency-domain correlations between platform motions and interface forces. (2) Rotor blade sailing, the phenomenon of large blade deflections occurring at low rotational speeds as the result of ship motion and unsteady aerodynamics, will continue to be investigated computationally and experimentally to discover how various conditions affect blade sailing and the extent to which the phenomenon can be attenuated using actively-controlled smart materials. Both rigid-segment and continuous beam modelling approaches are used to provide accurate computationally-efficient solutions well suited for parametric studies. (3) Postural stability research will continue to develop articulated dynamic models of humans on moving bases to determine the relationship between model complexity and fidelity and use the results to establish an accurate motion-induced interruption model. Inferences from these interrelated projects will be considered and generalized if possible in the context of the prescribed motion interface problem.