Analysis on two types of internal resonance of a suspended bridge structure with inclined main cables based on its sectional model

The performance of the cantilever beam autoparametric vibration absorber with a lumped mass attached at an arbitrary point on the beam span is investigated. The absorber would have a distinct feature that in addition to the two-to-one internal resonance, the one-to-three and one-to-five internal resonances would also occur between flexural modes of the beam by tuning the mass and position of the lumped mass. Special attention is paid on studying the effect of these resonances on increasing the effectiveness and extending the range of excitation amplitudes at which the autoparametric vibration absorber remains effective. The problem is formulated based on the third-order nonlinear Euler–Bernoulli beam theory, where the assumed-mode method is used for deriving the discretized equations of motion. The numerical continuation method is then applied to obtain the frequency response curves and detect the bifurcation points. The harmonic balance method is also employed for detecting the type of internal resonances between flexural modes by inspecting the frequency response curves corresponding to different harmonics of the response. Parametric studies on the performance of the absorber are conducted by varying the position and mass of the lumped mass, while the frequency ratio of the primary system to the first mode of the beam is kept equal to two. Results indicated that the one-to-five internal resonance is especially responsible for the considerable enhancement of the performance.

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Internal resonance characteristics of hyperelastic thin-walled cylindrical shells composed of Mooney–Rivlin materials

Thin-Walled Structures ◽

10.1016/j.tws.2021.107754 ◽

2021 ◽

Vol 163 ◽

pp. 107754

Author(s):

Wei Zhao ◽

Jing Zhang ◽

Wenzheng Zhang ◽

Xuegang Yuan

Keyword(s):

Internal Resonance ◽

Cylindrical Shells ◽

Thin Walled

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Damage Identification Method of Reinforced Concrete Bridge Structure based on Modal Technology

2020 IEEE International Conference on Industrial Application of Artificial Intelligence (IAAI) ◽

10.1109/iaai51705.2020.9332817 ◽

2020 ◽

Author(s):

Wei-Wei Zhan ◽

Xing-Hang Long ◽

Xu-Lan Gui

Keyword(s):

Reinforced Concrete ◽

Damage Identification ◽

Concrete Bridge ◽

Bridge Structure ◽

Reinforced Concrete Bridge ◽

Identification Method

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Smart Sensing of PSC Girders Using a PC Strand with a Built-in Optical Fiber Sensor

Applied Sciences ◽

10.3390/app11010359 ◽

2021 ◽

Vol 11 (1) ◽

pp. 359

Author(s):

Sung Tae Kim ◽

Hyejin Yoon ◽

Young-Hwan Park ◽

Seung-Seop Jin ◽

Soobong Shin ◽

...

Keyword(s):

Optical Fiber ◽

Prestressed Concrete ◽

Steel Wire ◽

Optical Fiber Sensor ◽

Fiber Reinforced Polymer ◽

Bridge Structure ◽

Fbg Sensor ◽

Prestressing Force ◽

Reinforced Polymer ◽

Loading Tests

This paper presents a multi-functional strand capable of introducing prestressing force in prestressed concrete (PSC) girders and sensing their static and dynamic behavior as well. This innovative strand is developed by replacing the core steel wire of the strand used in PSC structures with a carbon fiber-reinforced polymer (CFRP) wire with a built-in optical Fiber Bragg Grating (FBG) sensor. A full-scale girder specimen was fabricated by applying this multi-function strand to check the possibility of tracking the change of prestressing force at each construction stage. Moreover, dynamic data could be secured during dynamic loading tests without installing accelerometers and made it possible to obtain the natural frequencies of the structure. The results verified the capability to effectively manage the prestressing force in the PSC bridge structure by applying the PC strand with a built-in optical sensor known for its outstanding practicability and durability.

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Effect of Modelling Inhomogeneous Wave Conditions on Structural Responses of a Very Long Floating Bridge

Journal of Marine Science and Engineering ◽

10.3390/jmse9050548 ◽

2021 ◽

Vol 9 (5) ◽

pp. 548

Author(s):

Jian Dai ◽

Christos Stefanakos ◽

Bernt J. Leira ◽

Hagbart Skage Alsos

Keyword(s):

Water Environment ◽

Bridge Structure ◽

Inhomogeneous Wave ◽

Wave Condition ◽

Analysis And Design ◽

Inhomogeneous Waves ◽

Modelling Analysis ◽

Structural Responses ◽

Floating Bridge ◽

Wave Conditions

Floating bridges are suitable for connecting land parcels separated by wide and deep waterbodies. However, when the span of the crossing becomes very long, the water environment exhibits inhomogeneities which introduce difficulties to the modelling, analysis and design of the bridge structure. The wave inhomogeneity may be described by means of field measurement and/or numerical simulations. Both approaches face complications when the resolution is much refined. It is thus important to examine the effect of the resolution related to the modelling of inhomogeneous waves on the global structural responses. In this study, a hypothetical crossing at the Sulafjord is chosen, and the wave environment in the year 2015 at 10 positions along the crossing is numerically computed. Next, different inhomogeneous wave conditions are established based on the wave data at 3, 5, and 10 positions, respectively. Time-domain simulations are conducted to examine the effect of different modelling approaches of the inhomogeneous wave condition on the global responses of a long, straight and side-anchored floating bridge.

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Elimination of outlier measurements for damage detection of structures under changing environmental conditions

Structural Health Monitoring ◽

10.1177/1475921721998476 ◽

2021 ◽

pp. 147592172199847

Author(s):

William Soo Lon Wah ◽

Yining Xia

Keyword(s):

Damage Detection ◽

Multiple Regression ◽

Natural Frequencies ◽

Detection Method ◽

Detection Methods ◽

Structure Model ◽

Bridge Structure ◽

Beam Structure ◽

Dependent Variables ◽

The Difference

Damage detection methods developed in the literature are affected by the presence of outlier measurements. These measurements can prevent small levels of damage to be detected. Therefore, a method to eliminate the effects of outlier measurements is proposed in this article. The method uses the difference in fits to examine how deleting an observation affects the predicted value of a model. This allows the observations that have a large influence on the model created, to be identified. These observations are the outlier measurements and they are eliminated from the database before the application of damage detection methods. Eliminating the outliers before the application of damage detection methods allows the normal procedures to detect damage, to be implemented. A multiple-regression-based damage detection method, which uses the natural frequencies as both the independent and dependent variables, is also developed in this article. A beam structure model and an experimental wooden bridge structure are analysed using the multiple-regression-based damage detection method with and without the application of the method proposed to eliminate the effects of outliers. The results obtained demonstrate that smaller levels of damage can be detected when the effects of outlier measurements are eliminated using the method proposed in this article.

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