Mitigation of forced vibrations by semi-active control of local transfer of moments

Popławski, Błażej; Mikułowski, Grzegorz; Wiszowaty, Rafał; Jankowski, Łukasz

doi:10.1016/j.ymssp.2021.107733

Cited by 15 publications

(4 citation statements)

References 43 publications

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“…Thus, they are treated as rigid bodies. More details about these joints can be found in [ 42 , 43 , 44 ]. Steel rectangular beam profiles are connected with the joints via uncertain bolted connections whose stiffness is to be identified.…”

Section: Structure Under Investigationmentioning

confidence: 99%

Influence of Noise in Computer-Vision-Based Measurements on Parameter Identification in Structural Dynamics

Ostrowski

Błachowski

Mikułowski

et al. 2022

Sensors

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Nowadays, consumer electronics offer computer-vision-based (CV) measurements of dynamic displacements with some trade-offs between sampling frequency, resolution and low cost of the device. This study considers a consumer-grade smartphone camera based on complementary metal-oxide semiconductor (CMOS) technology and investigates the influence of its hardware limitations on the estimation of dynamic displacements, modal parameters and stiffness parameters of bolted connections in a laboratory structure. An algorithm that maximizes the zero-normalized cross-correlation function is employed to extract the dynamic displacements. The modal parameters are identified with the stochastic subspace identification method. The stiffness parameters are identified using a model-updating technique based on modal sensitivities. The results are compared with the corresponding data obtained with accelerometers and a laser distance sensor. The CV measurement allows lower-order vibration modes to be identified with a systematic (bias) error that is nearly proportional to the vibration frequency: from 2% for the first mode (9.4 Hz) to 10% for the third mode (71.4 Hz). However, the measurement errors introduced by the smartphone camera have a significantly lower influence on the values of the identified stiffness parameters than the numbers of modes and parameters taken into account. This is due to the bias–variance trade-off. The results show that consumer-grade electronics can be used as a low-cost and easy-to-use measurement tool if lower-order modes are required.

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Section: Structure Under Investigationmentioning

confidence: 99%

Influence of Noise in Computer-Vision-Based Measurements on Parameter Identification in Structural Dynamics

Ostrowski

Błachowski

Mikułowski

et al. 2022

Sensors

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“…However, these nodes can also be utilized to trigger the transfer of vibrational energy to high-order modes, which are more effectively damped by standard material damping mechanisms compared to low-order modes [19]. The control laws involved are either simple heuristics [20] or more formal and explicitly aimed at modal energy transfer [21]. These formulations focused on energetic measures of structural vibrations.…”

Section: Introductionmentioning

confidence: 99%

Semi-Active Sliding-Mode Control for Local Mitigation of Structural Vibrations by Means of on/Off Nodes

Ostrowski,

Jedlinska,

Poplawski

et al. 2023

10th ECCOMAS Thematic Conference on Smart Structures and Materials

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This contribution presents a sliding-mode control approach for the mitigation of vibrations in frame-like structures. The control is implemented in a semi-active manner, that is, without significant external control forces and substantial power consumption, which are typical for active control approaches. Here, the control is achieved through dynamic, lowcost modification of properties at selected structural nodes. The employed actuators have the untypical form of two-state hinges, which can switch between two extreme states: no transfer of bending moments (effectively a hinge) and full transfer of bending moments (a locked hinge or a typical frame node). Consequently, the control forces are dissipative and coupled to the response. Previous research in this area focused on purely energetic considerations, aiming for global damping of vibrations. In contrast, this paper formulates the control objective in terms of local displacements of a selected degree of freedom, which can be interpreted as the task of isolating it from external excitations. This formulation is employed to define the target sliding hyperplane. The state of the actuators is chosen such that the effective control forces push the structural state toward the target hyperplane. The approach is verified in a numerical example of a six-story shear-type structure subjected to random seismic excitation.

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“…In practical application, it often must bear different types of external excitation, which leads to harmful vibration of the beam and the connected structure, affecting the operation state of the equipment (Liu et al, 2021). In the past decades, the research on vibration control mainly focused on absorbing and consuming vibration energy, and developed a series of vibration reduction measures, such as the constrained damping materials (Lu et al, 2020), the tuned mass damper (Zhang et al, 2021), the nonlinear energy sink (Tsiatas and Karatzia, 2020), and the active vibration control based on external energy input (Poplawski et al, 2021), which play a very good role in structural vibration control. Recently, to reduce the vibration transmission between the simply supported beam and the connected structure, extending the vibration isolation bandwidth of the beam is an effective approach and has been paid more and more attention by scientists and engineers (Grossi and Quintana, 2008;Mao et al, 2017;Raei and Dardel, 2020).…”

Section: Introductionmentioning

confidence: 99%

Vibration isolation performance of simply supported beam installed with a negative stiffness device

Zhang

Cao

Liu

et al. 2022

Journal of Vibration and Control

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A negative stiffness device composed of two horizontal pre-compression springs is proposed to isolate the vibration of the simply supported beam. The nonlinear vibration equation of simply supported beam installed with a negative stiffness device is established by using Hamilton principle first. The lower degree of freedom dynamic equation of the system is derived by using Galerkin truncation approach. The influence of support position and negative stiffness parameters on the natural frequency of the beam are obtained from the modal analysis of the free vibration system. According to the dynamic internal force of the beam, the force transmissibility at the support end is defined and the displacement transmissibility of any point on the beam is also defined to facilitate the analysis of the vibration isolation effect. The influence of negative stiffness support parameters on the amplitude–frequency curve and the transmissibility curve of the simply supported beam is discussed. The results show that the fundamental frequency of the system can be significantly reduced by the negative stiffness device, while the frequencies of high-order modes are changed a little bit only. Increasing the horizontal spring stiffness will reduce the first-order resonance frequency and the initial frequency of vibration isolation. Consequently, the aim of lower frequency vibration isolation for the simply supported beam can be achieved. This paper provides an effective approach to the vibration isolating design of flexible structures.

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Mitigation of forced vibrations by semi-active control of local transfer of moments

Cited by 15 publications

References 43 publications

Influence of Noise in Computer-Vision-Based Measurements on Parameter Identification in Structural Dynamics

Influence of Noise in Computer-Vision-Based Measurements on Parameter Identification in Structural Dynamics

Semi-Active Sliding-Mode Control for Local Mitigation of Structural Vibrations by Means of on/Off Nodes

Vibration isolation performance of simply supported beam installed with a negative stiffness device

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