A method for estimation of rubber bushing stiffness parameters is presented. Four individual rubber bushings, mounted in a car rear subframe are considered. A traditional model of the bushing elements using a generalised spring model, known as a CBUSH element in Nastran, is compared to a geometrically more realistic approach where the bushing is modelled with solid elements and a linear elastic material model. Each bushing is mass loaded to better reveal the bushing’s dynamic behaviour in a lower frequency range of interest. In an initial step, the overall subframe model is updated towards test data. In a second step, the bushing parameters are updated. Three nominally identical components are used to investigate the spread between the identified parameters. The model updating procedure is based on frequency responses and equalised damping. The undamped behaviour at frequencies below 300 Hz are considered. To quantify the parameter uncertainty, with respect to measurement noise for each individual, an uncertainty quantification procedure is proposed, using a linear-in-parameters surrogate model with bootstrapping.

中文翻译：

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多个名义上相同的汽车零部件的模型更新

提出了一种估计橡胶衬套刚度参数的方法。考虑了安装在汽车后副车架上的四个单独的橡胶衬套。使用广义弹簧模型的传统衬套元件模型（在 Nastran 中称为 CBUSH 元件）与几何上更现实的方法进行了比较，后者使用实体元件和线弹性材料模型对衬套进行建模。每个套管都带有质量负载，以更好地揭示套管在感兴趣的较低频率范围内的动态行为。在初始步骤中，整个子帧模型针对测试数据进行更新。第二步，更新套管参数。三个名义上相同的组件用于研究已识别参数之间的分布。模型更新程序基于频率响应和均衡阻尼。考虑了频率低于 300 Hz 时的无阻尼行为。为了量化参数不确定性，就每个人的测量噪声而言，提出了一种不确定性量化程序，使用带自举的线性参数替代模型。