Nonlinear time series analysis using Bayesian recurrence plot quantification to analyse the dynamics of friction-induced vibrations, in particular wear and damping in artificial synovial joints.

使用贝叶斯递归图量化的非线性时间序列分析来分析摩擦引起的振动的动力学，特别是人工滑膜关节中的磨损和阻尼。

• 批准号: 314996946
• 负责人: Dr. Sebastian Oberst
• 金额: --
• 依托单位: Institut für Strukturdynamik
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/314996946?language=en
• 关键词: Nonlinear; time; series; analysis; using

Unwanted vibrations particularly owing to friction are encountered in various industries. While vibrations usually decay with time owing to damping, friction-induced instabilities cause positive and energy providing positive system damping. Positive damping lets vibration amplitudes grow, leading to excessive wear and premature product failure. These positive feedback loops, once established, also lead to audible noises, which are also problematic in artificial synovial joints, as found in total knee or hip replacements. In the past most research concentrated on reducing wear particles or improving their biocompatibility using experimental testing. However, damping and lubrication considering the cartilage or synovial fluid and their effect on artificial synovial joints friction has never been studied numerically or from the dynamics point of view. Here, nonlinear dynamics as output quantity is employed to develop highly innovative Bayesian recurrence plot quantification analysis measures based on recurrence plots and Bayesian updating in combination with the Maximum Entropy Theory. Dynamic variants with credibility bounds, embedding parameters, and unstable periodic orbits are estimated. Attractor-based templates are used to generate inversely reduced-order models to explore the nonlinear dynamics. The basin of attraction and its linear stability boundary is estimated using the templates and analytical models. The influence of noise on invariant estimations in practical measurements is considered. This novel methodology is applied to nonlinear benchmark systems and then to a large database of experimental biomechanical tests of hip and knee implants, considering different driving parameters, various lubricants and running times. By using sophisticated vibration testing over laser vibrometry and kinematics determined over Roentgen stereo photogrammetric analysis, in a bottom up process, a high-fidelity finite element model coupled to computational fluid dynamics simulations is setup to study artificial synovial hip joint with focus on lubrication and squeeze film damping considering the synovial fluid. Modern methods of uncertain parameter identification are employed taking into account the component, the subassembly and the assembly level with and without fluid. Numerical time traces are then analysed by applying the novel Bayesian recurrence plot quantification measures and invariant estimations which allow the numerical model being further updated, both evidence- and response-based and in a top-down approach. Different stages according to the gate cycle are analysed rendering the model updating as a multi-stage process and allow finally to study the effect of the synovial fluids thin film on damping and dissipation. Findings will lead to significant insights of underlying the physics in friction and wear in artificial synovial joints which can be used to design quieter hip inserts by making use of optimised thin film or squeeze film damping.

在各个行业中遇到了尤其是由于摩擦而造成的不必要振动。尽管振动通常由于阻尼而随着时间的流逝而衰减，但摩擦引起的不稳定性会引起正和能量提供正系统阻尼。阳性阻尼可以使振动振幅增长，从而导致过度磨损和过早的产品故障。这些积极的反馈回路一旦建立，也会导致声音噪声，在人造滑膜中也有问题，如在总膝盖或髋关节置换中所示。过去，大多数研究都集中在减少磨损颗粒或使用实验测试改善其生物相容性。然而，考虑软骨或滑液及其对人工滑膜摩擦的影响，从未通过数值或从动力学的角度研究它们对人工滑膜摩擦的影响。在这里，采用非线性动力学作为输出数量来开发基于复发图和贝叶斯更新与最大熵理论相结合的高度创新的贝叶斯复发图量化分析测量指标。估计具有信誉范围，嵌入参数和不稳定周期轨道的动态变体。基于吸引子的模板用于生成倒数降低的模型以探索非线性动力学。使用模板和分析模型估算吸引力及其线性稳定性边界的盆地。考虑了噪声对实际测量中不变估计的影响。这种新型方法应用于非线性基准系统，然后应用于髋关节和膝盖植入物的实验生物力学测试的大型数据库，考虑到不同的驾驶参数，各种润滑剂和运行时间。通过对roentgen立体摄影测量分析确定的激光振动测试进行复杂的振动测试，在自下而上的过程中，高保真有限的元件模型与计算流体动力学模拟相连，以研究人工髋关节，将人工髋关节与集中在润滑和挤压胶片上的胶片胶片上进行研究。现代的不确定参数识别方法被考虑到有或没有流体的组件，子组件和组装水平。然后，通过应用新颖的贝叶斯复发图量化度量和不变估计来分析数值时间迹线，从而使数值模型进一步更新，无论是循证和基于响应还是在自上而下的方法中。根据栅极周期分析了不同的阶段，将模型更新作为多阶段过程进行分析，并最终允许研究滑液薄膜对阻尼和耗散的影响。调查结果将导致在人工滑膜中摩擦物理和磨损的基本见解，可通过利用优化的薄膜或挤压膜阻尼来设计更安静的臀部插入物。