Nonlinear vibration of series-parallel fluid-conveying spatial-pipe systems with constrained-layer damping

International Journal of Mechanical Sciences, Год журнала: 2025, Номер unknown, С. 110334 - 110334

Опубликована: Май 1, 2025

Язык: Английский

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Relationship of flow pattern, vibration, and noise in automobile refrigerant system and flow pattern identification based on convolutional neural network

Physics of Fluids, Год журнала: 2024, Номер 36(9)

Опубликована: Сен. 1, 2024

In recent years, the flow-induced vibration and noise in automotive refrigerant system gradually become main factor affecting driving comfort. However, relationship of flow pattern, vibration, is not clear, pattern identification easy but necessary. this paper, a series experiments are conducted to investigate flow-induce near thermal expansion valve an automobile system. The closely related startup processes. Mist flow, which contains more mist two-phase mixture than transition wispy-annular leads largest amplitude strong broadband hiss noise. Moreover, increase compressor speed promotes time domain has no effect on distribution peaks frequency spectrum. Finally, short-time Fourier transform convolutional neural network combined method for developed based After using transfer learning data augmentation, four trained architectures show relatively high accuracy above 94% test set. Among them, ResNet34 only highest 98.8% also can recognize each type pattern. generalization help engineers patterns air conditioning without visualization need measure sound signals.

Язык: Английский

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Dynamics and Reliability Design of Tilt-Rotor Aircraft with Nonlinearity and Stochasticity

AIAA Journal, Год журнала: 2025, Номер unknown, С. 1 - 20

Опубликована: Май 6, 2025

This study examines the reliability of a four-degree-of-freedom tilt-rotor model in presence random load, taking into account both cubic and freeplay nonlinearities. We discuss Hopf bifurcation, multistability phenomena, dynamic responses tilt-rotor. To analyze reliability, we firstly develop dimensionality reduction method based on diffusion approximation theory perform effects stochasticity behaviors detail. Several undesirable which ultimately result failure rotor structure, are induced by load. Subsequently, is defined analyzed accordance with principles damage accumulation. The impacts varying parameters examined. Additionally, nonlinear energy sink (NES) incorporated to mitigate vibration accumulation model, thereby enhancing reliability. Reliability regions for presented delineate safety parameter range. findings demonstrate that incorporation NES markedly enhances model’s research offers novel insights design aircraft.

Язык: Английский

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Data-Driven Analysis of Probability Density for Nonlinear Stochastic Duffing-van der Pol Systems Using BP Neural Networks

Probabilistic Engineering Mechanics, Год журнала: 2025, Номер unknown, С. 103775 - 103775

Опубликована: Май 1, 2025

Язык: Английский

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Analysis of dynamic response mechanism and optimization of nonlinear oscillator with nonlinear energy sink under randomly disordered periodic excitation

Nonlinear Dynamics, Год журнала: 2025, Номер unknown

Опубликована: Май 27, 2025

Язык: Английский

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