Modal analysis and dynamic response of two adjacent single-degree-of-freedom systems linked by spring-dashpot-inerter elements
Modal analysis and dynamic response of two adjacent single-degree-of-freedom systems linked by spring-dashpot-inerter elements
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DOI：
10.1016/j.engstruct.2018.07.048
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发表时间：
2018-11
影响因子：
5.5
通讯作者：
M. Basili;M. De Angelis;D. Pietrosanti
中科院分区：
文献类型：
--
作者：
M. Basili;M. De Angelis;D. Pietrosanti
本文阐述了一种新的结构配置的动力学表示的两个相邻的单自由度（2-ASDOF）系统耦合的弹簧-阻尼器-惯性元件并联连接。如果仅用弹簧和/或惯性器实现连接，则该连接是保守的，而当还添加阻尼器时，则变为非保守的。研究的第一部分涉及系统模态分析：考虑不同的连接方案，以调查每个连接参数对耦合系统模态特性的影响。结果表明，对于保守连接，由于特征值问题存在封闭形式的解，因此可以解析地推导出模态特性。对于非保守连接，采用状态空间描述，并进行复模态分析（推导伪频率、伪阻尼因子和复模态）。耦合系统频率的允许和不允许区域是个性化的：频率位于左侧、右侧或非耦合频率内，这取决于连接参数的选择值。与每种情况相关联，描述了典型的模式振型。当连接参数取特定值时，系统的特殊行为有利于结构控制。本文的第二部分说明了非常简单的输入条件下的系统动力学：进行初始条件下的自由振动和基础谐波运动的响应。根据模态分析的结果，它强调，它是可以适当地选择连接参数，以便有：（i）最快的衰减的结构响应的情况下的自由振动和（ii）最小的响应放大的情况下的谐振器。
This paper illustrates the dynamics of a novel structural configuration represented by two adjacent single-degree-of-freedom (2-ASDOF) systems coupled by a connection with spring-dashpot-inerter elements arranged in parallel. The connection is conservative if the link is realized only with spring and/or inerter, whereas becomes nonconservative when also the dashpot is added. The first part of the study concerns the system modal analysis: different linking schemes are considered in order to investigate the influence of each connection parameter on the coupled system modal properties. It is shown that, for conservative connection, modal properties are analytically derived because the eigenvalue problem admits closed-form solutions. For nonconservative connection, instead, the state-space description is adopted and the complex modal analysis is carried out (deriving pseudo-frequencies, pseudo-damping factors and complex modes). Admissible and not-admissible zones for the frequencies of the coupled system are individuated: frequencies are positioned on the left, on the right or within the uncoupled ones, depending on the values chosen for the connection parameters. Associated to each case, typical patterns for mode shapes are depicted. Peculiar behaviors of the system, advantageous for structural control purposes, emerge when the connection parameters assume specific values. The second part of the paper illustrates the system dynamics to very simple input conditions: the response to free vibration with initial conditions and to base harmonic motion is carried out. Based on the findings obtained from modal analysis, it is highlighted that it is possible to properly select the connection parameters in order to have: (i) the most rapid decay of the structural response in case of free vibrations and (ii) the minimum response amplification for both oscillators in case of harmonic motion.