This study examines two basic substructuring schemes for shake table tests where the dynamics of the table is significantly affected by a specimen. The hybrid simulation (HS) scheme, commonly adopted in substructuring experiments, directly uses the output of a numerical substructure as an input signal to a physical substructure. The dynamical substructuring system (DSS) scheme, developed long after HS, uses feedforward and feedback controllers to minimise the control error produced by the outputs of numerical and physical substructures. Before examining these two schemes, this study introduces a systematic formulation for dividing a multi‐degree‐of‐freedom emulate system into a numerical substructure and a physical substructure with a shake table. Then, controller designs for HS and DSS are discussed for the substructures. The two schemes with basic control approaches were numerically examined through substructuring tests for a linear 3DOF emulate system. DSS with stability was powerful even under a control condition with a pure time delay and inaccurate estimation of the table dynamics, whereas these factors degraded the HS performance. In additional simulations in which nonlinear characteristics were considered, the performance of DSS (HS) was degraded mainly by the nonlinear (inaccurate estimation of the table dynamics). It was found that the stability of substructures with nonlinear characteristics could be roughly assessed by the Nyquist stability criterion. These simulations with/without nonlinear characteristics clarified the performances of the HS and DSS schemes through basic control approaches and stability analysis under practical conditions.

中文翻译：

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摇表测试的两个子计划的基础检查

这项研究研究了两种用于振动台测试的基本子结构方案，其中振动台的动力学受到样本的影响很大。子结构实验中通常采用的混合仿真（HS）方案直接将数字子结构的输出用作物理子结构的输入信号。动态子结构系统（DSS）方案是在HS以后很久才开发的，它使用前馈和反馈控制器来最大程度地减少数字和物理子结构的输出所产生的控制误差。在检查这两种方案之前，本研究介绍了一种系统化的公式，用于将多自由度仿真系统划分为数值子结构和带有振动台的物理子结构。然后，讨论了用于子结构的HS和DSS的控制器设计。通过对线性3DOF仿真系统的子结构测试，对两种具有基本控制方法的方案进行了数值检验。具有稳定功能的DSS甚至在具有纯时间延迟和对表动态的估计不准确的控制条件下也很强大，而这些因素会降低HS性能。在考虑了非线性特性的其他模拟中，DSS（HS）的性能主要由于非线性（表动态的不准确估算）而降低。已经发现，具有非线性特征的子结构的稳定性可以通过奈奎斯特稳定性准则粗略地评估。这些具有/不具有非线性特性的仿真通过基本控制方法和在实际条件下的稳定性分析，阐明了HS和DSS方案的性能。