Study on Vibration Response of a Non-Uniform Beam With Nonlinear Boundary Condition

Wang, Peng; Wu, Nan; Luo, Haitao; Sun, ZhengMing

doi:10.22190/fume210324045w

Cited by 6 publications

(3 citation statements)

References 37 publications

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“…In practical engineering applications, different types of beam structures are widely used, because they can optimize weight and change strength by changing the cross-sectional area and material properties. Uniform and non-uniform beams, sandwich composite structures, and honeycomb structures are increasingly used in many fields of engineering and practically always used as structural elements [1,2].…”

Section: Introductionmentioning

confidence: 99%

Smoke detector placement in compartments with honeycomb ceiling: A numerical study

et al. 2023

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One of the most interesting problems in fire detection system design is the problem referred to as detector position on a ?honeycomb ceiling?, because beams and joists affect stratification of smoke and, consequently, smoke detector response time. The aim of this paper is to determine optimal smoke detector placement - on the underside of beams or on the structural slab in the cells. On the basis of rules of standards for smoke detector location, the Large Eddy Simulation method of Fire Dynamics Simulator software package was employed to investigate the effects of ?honeycomb? density on smoke detector response time. The simulation results show that the columns, beams, joists and similar structural elements affect stratification of smoke and, consequently, smoke detector response time. In the case when the honeycomb cells are small, the detectors on the underside of the beams react faster because the smoke does not enter the cells in sufficient quantity to activate the optical smoke detector located on the structural plate in the cells that form the beams. On the basis of the obtained results, a satisfactory solution for most possible situations that could occur in practice has been proposed.

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Section: Introductionmentioning

confidence: 99%

Smoke detector placement in compartments with honeycomb ceiling: A numerical study

et al. 2023

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“…17 El-Dib studied the properties of complex Helmholtz-Duffing oscillator arising in the fluid mechanics. 18,19 More recently, there are many analytical and numerical methods to find an approximate solution of a nonlinear oscillator, such as the variational iteration method, [20][21][22] the homotopy perturbation, [23][24][25][26] the Hamiltonian approach, [27][28][29] Adomian decomposition method, 30 and others. 31,32 However, the previous research focused on searching for its approximate solution, and the pulldown instability and asymmetric period have not yet studied in literature.…”

Section: Introductionmentioning

confidence: 99%

Symmetry-breaking and pull-down motion for the Helmholtz–Duffing oscillator

Niu,

He,

Alsolami

2023

Journal of Low Frequency Noise, Vibration and Active Control

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An accurate frequency of the Helmholtz–Duffing oscillator is obtained by a sophisticated modification of He’s frequency formulation. The pull-down instability existing in the symmetric breaking phenomenon is a newly discovered dynamic motion for oscillators with even nonlinearities. A criterion for predicting the asymmetrical amplitude motion and the pull-down instability is built by measuring the amplitude change. The good matching performance between the analytic results and numerical ones indicates that the criterion offers a starting point for future research into the pull-down phenomenon, and opens a new path for studying more complex nonlinear oscillators with even nonlinearities.

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“…This distortion in the images can lead to the lack of clarity that will later decrease the accuracy rate of the whole system. In order to significantly reduce or even prevent the motion blur effect in images, cameras are mounted on gimbals to suppress vibrations transmitted from the moving vehicle, as well as to allow the rotation of cameras and on-line control of their orientation so as to follow the tracks reliably [9]. Furthermore, the cameras are mounted in special housing, which is vibration isolated [10] to lower the level of camera vibrations.…”

Section: Introductionmentioning

confidence: 99%

Dealing with Low Quality Images in Railway Obstacle Detection System

et al. 2022

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Object recognition and classification as well as obstacle distance calculation are of the utmost importance in today’s autonomous driving systems. One such system designed to detect obstacle and track intrusion in railways is considered in this paper. The heart of this system is the decision support system (DSS), which is in charge of making complex decisions, important for a safe and efficient autonomous train drive based on the information obtained from various sensors. DSS determines the object class and its distance from a running train by analyzing sensor images using machine learning algorithms. For the quality training of these machine learning models, it is necessary to provide training sets with images of adequate quality, which is often not the case in real-world railway applications. Furthermore, the images of insufficient quality should not be processed at all in order to save computational time. One of the most common types of distortion which occurs in real-world conditions (train movement and vibrations, movement of other objects, bad weather conditions, and day and night image differences) is blur. This paper presents an improved edge-detection method for the automatic detection and rejection of images of inadequate quality regarding the blur level. The proposed method, with its improvements convenient for railway application, is compared with several other state-of-the-art methods for blur detection, and its superior overall performance is demonstrated.

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Study on Vibration Response of a Non-Uniform Beam With Nonlinear Boundary Condition

Cited by 6 publications

References 37 publications

Smoke detector placement in compartments with honeycomb ceiling: A numerical study

Smoke detector placement in compartments with honeycomb ceiling: A numerical study

Symmetry-breaking and pull-down motion for the Helmholtz–Duffing oscillator

Dealing with Low Quality Images in Railway Obstacle Detection System

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