Dynamic substructuring (DS) methods encompass a range of techniques to decompose large structural systems into multiple coupled subsystems. This decomposition has the principle benefit of reducing computational time for dynamic simulation of the system. In this context, DS methods may form an essential component of hybrid simulation, wherein they can be used to couple physical and numerical substructures at reduced computational cost. Since most engineered systems are inherently nonlinear, particular potential lies in incorporating nonlinear methods in existing substructuring schemes which are largely linear methods. The most widely used and studied DS methods are classical linear techniques such as the Craig-Bampton (CB) method. However, as linear methods they naturally break down in the presence of nonlinearities. Recent advancements in substructuring have involved the development of enrichments to linear methods, which allow for some degree of nonlinearity to be captured. The use of mode shape derivatives has been shown to be able to capture geometrically non-linear effects as an extension to the CBmethod. Other candidates include the method of Finite Element Tearing and Interconnecting. In this work, a virtual hybrid simulation is presented in which a linear elastic vehicle frame supported on four nonlinear spring damper isolators is decomposed into separate domains. One domain consisting of the finite element model of the vehicle frame, which is reduced using the CB method. The second domain consists of the nonlinear isolators whose restoring forces are characterised by nonlinear spring and damper forces. Coupling between the models is carried out using a Lagrange multiplier method and time series simulations of the system are conducted and compared to the full global system with regards to simulation time and accuracy.

中文翻译：

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局部非线性系统的动态子结构化

动态子结构化 (DS) 方法包含一系列技术，可将大型结构系统分解为多个耦合子系统。这种分解的主要优点是减少系统动态仿真的计算时间。在这种情况下，DS 方法可以构成混合模拟的重要组成部分，其中它们可用于以降低的计算成本耦合物理和数值子结构。由于大多数工程系统本质上是非线性的，因此在现有的主要是线性方法的子结构化方案中加入非线性方法具有特殊的潜力。最广泛使用和研究的 DS 方法是经典的线性技术，例如 Craig-Bampton (CB) 方法。然而，作为线性方法，它们在非线性的存在下自然会崩溃。子结构化的最新进展涉及对线性方法的丰富发展，这允许捕获某种程度的非线性。模式形状导数的使用已被证明能够捕捉几何非线性效应，作为 CB 方法的扩展。其他候选方法包括有限元撕裂和互连方法。在这项工作中，提出了一个虚拟混合仿真，其中支撑在四个非线性弹簧阻尼器隔振器上的线弹性车架被分解为单独的域。一个域由车架的有限元模型组成，使用 CB 方法对其进行了缩减。第二个域由非线性隔振器组成，其恢复力以非线性弹簧力和阻尼力为特征。