标题： 动态子结构应用中稳定耦合状态空间模型的计算 显示英文标题

标题： On the computation of stable coupled state-space models for dynamic substructuring applications

摘要： 本文旨在介绍一种方法，通过引入两种新方法来计算动态子结构应用中的稳定耦合状态空间模型：a) 一种在不依赖使用无阻尼RCMs（剩余补偿模态）的情况下施加牛顿第二定律的程序；b) 一种在不稳定耦合状态空间模型上施加稳定性的新方法。 稳定性的实现是通过将不稳定的模型分为两个不同的模型，一个由稳定极点（稳定模型）组成，另一个由不稳定极点（不稳定模型）组成。 然后，强制不稳定状态空间模型的极点变得稳定，从而计算出一个稳定的状态空间模型。 随后，为了确保稳定模型的频响函数（FRFs）与不稳定模型的频响函数良好匹配，采用最小二乘频域（LSFD）方法来更新由复共轭极对组成的稳定模型的模态参数。 通过利用实验数据，展示了所提出方法的有效性。 事实上，通过利用真实系统的频响函数，计算出了符合牛顿第二定律的准确状态空间模型。 然后，使用识别出的状态空间模型进行解耦和耦合操作，无论解耦/耦合操作得到的模型是否不稳定。 随后，通过遵循本文提出的方法，对计算得到的不稳定耦合模型施加稳定性。 该方法在这些数据上表现良好。 此外，本文还表明，使用该方法获得的耦合状态空间模型适用于时域分析和仿真。 显示英文摘要

摘要： This paper aims at introducing a methodology to compute stable coupled state-space models for dynamic substructuring applications by introducing two novel approaches targeted to accomplish this task: a) a procedure to impose Newtons's second law without relying on the use of undamped RCMs (residual compensation modes) and b) a novel approach to impose stability on unstable coupled state-space models. The enforcement of stability is performed by dividing the unstable model into two different models, one composed by the stable poles (stable model) and the other composed by the unstable ones (unstable model). Then, the poles of the unstable state-space model are forced to be stable, leading to the computation of a stabilized state-space model. Afterwards, to make sure that the Frequency Response Functions (FRFs) of the stabilized model well match the FRFs of the unstable model, the Least-Squares Frequency Domain (LSFD) method is exploited to update the modal parameters of the stabilized model composed by the pairs of complex conjugate poles. The validity of the proposed methodologies is presented and discussed by exploiting experimental data. Indeed, by exploiting the FRFs of a real system, accurate state-space models respecting Newton's second law are computed. Then, decoupling and coupling operations are performed with the identified state-space models, no matter the models resultant from the decoupling/coupling operations are unstable. Stability is then imposed on the computed unstable coupled model by following the approach proposed in this paper. The methodology proved to work well on these data. Moreover, the paper also shows that the coupled state-space models obtained using this methodology are suitable to be exploited in time-domain analyses and simulations.