Reina Salvatore, Arcos Robert, Clot Arnau, Romeu Jordi
Acoustical and Mechanical Engineering Laboratory (LEAM), Universitat Politècnica de Catalunya (UPC), C/Colom 11, Terrassa 08222, Barcelona, Spain.
Department of Mechanical Engineering, Escuela Politécnica Nacional, Ladrón de Guevara E11-253, Quito 17-01-2759, Ecuador.
Materials (Basel). 2020 Jun 27;13(13):2889. doi: 10.3390/ma13132889.
The assessment of the dynamic behaviour of resilient elements can be performed using the indirect method as described in the standard ISO 10846-3. This paper presents a methodology for control the error on the estimation of the frequency response functions (FRF) required for the application of the indirect method when sweep sine excitation is used. Based on a simulation process, this methodology allows for the design of the sweep sine excitation parameters, i.e., the sweep rate and the force amplitude, to control three types of errors associated to the experimentally obtained FRF in the presence of background noise: a general error of the FRF in a selected frequency range, and the errors associated to the amplitude and the frequency of the FRF resonance peak. The signal processing method used can be also tested with this methodology. The methodology has been tested in the characterisation of two different resilient elements: an elastomer and a coil spring. The simulated error estimations has been found to be in good agreement with the errors found in the measured FRF. Furthermore, it is found that for large signal-to-noise ratios, both sweep rate and force amplitude significantly affect the FRF estimation error, while, for small signal-to-noise ratios, only the force amplitude can control the error efficiently. The current methodology is specially interesting for laboratory test rigs highly used for the dynamic characterisation of resilient elements which are required to operate efficiently, since it can be used for minimising test times and providing quality assurance. Moreover, the application of this methodology would be specially relevant when characterisation is done in noisy environments.
可以使用标准ISO 10846-3中所述的间接方法来评估弹性元件的动态行为。本文提出了一种方法，用于在使用扫频正弦激励时，控制间接方法应用所需的频率响应函数（FRF）估计中的误差。基于一个模拟过程，该方法允许设计扫频正弦激励参数，即扫频速率和力幅，以控制在存在背景噪声的情况下与实验获得的FRF相关的三种误差：选定频率范围内FRF的一般误差，以及与FRF共振峰的幅度和频率相关的误差。所使用的信号处理方法也可以用该方法进行测试。该方法已在两种不同弹性元件的特性描述中进行了测试：一种是弹性体，另一种是螺旋弹簧。发现模拟误差估计与测量的FRF中发现的误差非常吻合。此外，还发现对于大信噪比，扫频速率和力幅都会显著影响FRF估计误差，而对于小信噪比，只有力幅可以有效地控制误差。当前的方法对于高度用于弹性元件动态特性描述且需要高效运行的实验室试验台特别有意义，因为它可用于减少测试时间并提供质量保证。此外，当在噪声环境中进行特性描述时，该方法的应用将特别相关。
