Article
Engineering, Mechanical
Kaikui Zheng, Youxi Lin, Tingzheng Lai, Chenghui Gao, Ming Liu, Zhiying Ren
Summary: The study investigated the use of waste foundry resin-bonded sand as a substitute for copper in resin-based brake material. It found that the waste sand was more favorable for improving the overall friction and wear properties of the material compared to copper. Waste sand benefited the material by forming a friction layer, leading to increased friction coefficient and stability. Brake material with 10-15% waste sand showed excellent heat-fade resistance.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Engineering, Mechanical
Tomohiro Toyoda, Ryo Yasuike, Toshihiro Noda
Summary: In this study, a elasto-plastic constitutive model of friction incorporating the concept of superloading surface was developed based on the subloading friction model. The proposed model achieves a smooth transition of friction by describing the evolution rule of structure, treating the state with static friction coefficient larger than kinetic friction coefficient as the bulkiness of structure. The positive definiteness of the plastic multiplier, loading condition, and material parameters were derived, and the validity of the proposed model in accordance with the subloading-friction model was confirmed through a stick-slip simulation of a mass-spring system.
TRIBOLOGY INTERNATIONAL
(2024)
Article
Acoustics
Jiahui Peng, Liang Wang, Bochen Wang, Minjuan Yuan, Wei Xu
Summary: A new path integration method is proposed for stochastic dynamical systems excited by Poisson white noise. It constructs an efficient one-step transition probability density function matrix based on a decoupling probability mapping. The method can handle multiple impulses occurring in a one-step transition time interval and considers the randomness of the impulse instant.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Yuhong Li, Zhida Ma, Peng Zhou, Siyang Zhong, Xin Zhang
Summary: In this study, we numerically investigate the aerodynamic and aeroacoustic performance of a hexacopter for urban air mobility. The results show that close placement of rotors leads to thrust fluctuations and increased sound pressure level. The presence of connecting arms generates additional noise, while the fuselage has little impact on total thrust and noise generation.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Longkai Zheng, Fengming Li, Zhijing Wu, Shurui Wen
Summary: A novel strategy is proposed for the dynamic modelling and quality factor evaluation of hemispherical shell resonators (HSR) considering the coupling of hemispherical shell and support rod. The artificial spring technique is introduced to simulate arbitrary boundary conditions. Hamilton's principle with the Rayleigh-Ritz method is employed to establish the equation of motion and obtain the natural frequencies of the HSR. The thermal energy method is applied to evaluate the thermoelastic damping (TED) of the HSR. The model of anchor loss is based on a separation and transfer method. The present theoretical model is validated through comparisons with published literature and finite element method (FEM). The effects of boundary conditions, geometrical parameters, and material properties on the vibration behaviors and quality factors of the HSR are analyzed.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
N. Aberkane-Gauthier, V. Romero-Garcia, D. Lecoq, M. Moleron, C. Lagarrigue, C. Pezerat
Summary: The dispersion and scattering properties of a soft solid plate with solid cylindrical inclusions embedded in it are investigated theoretically and numerically in this study. The system takes into account both the vibroacoustic coupling and the presence of viscoelastic losses. The presence of the inclusions introduces resonant and antiresonant phenomena, leading to an elastic band-gap and destructive modal interference in the soft solid plate.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Alexander N. Carr, Joel B. Lonzaga, Steven A. E. Miller
Summary: This study examines the effects of atmospheric boundary layer turbulence on the loudness variability of a sonic boom. The results show that the standard deviations of loudness metrics collapse across different convection levels of turbulence for small propagation distances. Additionally, the distribution of loudness metrics can be well approximated by a normal distribution for a given range of propagation distances and becomes increasingly skewed as distance increases.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
M. Amabili, H. R. Moghaddasi
Summary: Studies on nonlinear vibrations of circular cylindrical shells containing fluid have focused mostly on thin simply supported shells, leaving a lack of research on the behavior of thick cantilevered shells with shear and thickness deformations. This article presents, for the first time, models of thin and thick circular cylindrical shells with clamped-free boundary conditions based on the third-order shear deformation theory with thickness stretch. The derived governing differential equations describe the shell-fluid interaction. Results show that increasing the fluid level and decreasing the shell thickness in linear free vibration analysis significantly raise the fluid free-surface wave elevation, limiting the application of linear sloshing theory. The presence of the fluid changes the nonlinear behavior from softening to hardening, and intensifies the shell thickness deformation. Additionally, the contained liquid reduces the circumferential dynamic contraction caused by large amplitude vibrations.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Chaoyang Jiang, Danielle Moreau, Charitha de Silva, Con Doolan
Summary: This study numerically investigates the noise generation and flow characteristics of a forced-transitioned NACA 0012 airfoil with a micro-tube porous trailing edge. The results show that the micro tube structure reduces low-frequency trailing-edge noise and induces additional high-frequency noise through flow permeation. The interaction between flow permeation and boundary layer turbulence is the main cause for the noise reduction.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Mohammad Amin Faghihi, Hossein Mohammadi, Ehsan Azadi Yazdi, Mohammad Eghtesad, Shabnam Tashakori
Summary: This paper presents an integrated model to study the axial-torsional dynamics of a distributed drill string. By mathematical modeling, the characteristics of the drill string dynamics are explored. The findings contribute to improving drilling efficiency and reducing failures.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Zbynek Sika, Jan Krivosej, Tomas Vyhlidal
Summary: This paper presents a novel design of a compact six degrees of freedom active vibration absorber with six identical eigenfrequencies. The objective is to completely suppress the vibration of a machine structure with six motion components. By utilizing a Stewart platform structure equipped with six active legs, a spatial unifrequency absorber with six identical eigenfrequencies is achieved. The design is optimized using a correction feedback and active delayed resonator feedback.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Zhuogeng Zhang, Hongli Ji, Chongcong Tao, Jinhao Qiu, Li Cheng
Summary: This study introduces a new method to suppress panel flutter in supersonic flow using an add-on acoustic black hole (AABH). Numerical simulations demonstrate that the AABH effectively increases the critical flutter velocity and stabilizes the panel, reducing flutter amplitude.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Jiajia Zhang, Shan Yin, Bingyong Guo, Yang Liu
Summary: This paper presents a theoretical and experimental study on a universal vibro-impact system with bidirectional drift. The system exhibits various bifurcations and unpredictable motions under different excitation frequencies and amplitudes.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Viktor Hruska, Jean-Philippe Groby, Michal Bednarik
Summary: This study numerically and experimentally analyzes the amount and practical source of losses required for rectangular sonic black holes in air to effectively absorb low-frequency sound. The results show that in the presence of solely viscothermal losses, only high-order Fabry-Perrot resonances are likely to be critically coupled in realistic rectangular sonic black holes, resulting in absorption peaks that do not reach unity at low frequencies. To solve this issue, slits of rectangular sonic black holes are partially filled with porous materials, which significantly improves the absorption coefficient, especially at frequencies below the viscous/inertial transition frequency of the porous material.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Silouane de Reboul, Emmanuel Perrey-Debain, Nicolas Zerbib, Stephane Moreau
Summary: This paper presents a frequency domain numerical method for solving the propagation of sound waves in a three-dimensional domain with rotating obstacles. The method uses domain decomposition to embed rotating parts in a cylindrically-shaped domain and employs Frequency Scattering Boundary Conditions to achieve transmission conditions between fixed and rotating domains.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Sandip Chajjed, Mohammad Khalil, Dominique Poirel, Chris Pettit, Abhijit Sarkar
Summary: This paper reports the generalization of the Bayesian formulation of the flutter margin method, which improves the predictive performance by incorporating the joint prior of aeroelastic modal parameters. The improved algorithm reduces uncertainties in predicting flutter speed and can cut cost by reducing the number of flight tests.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Hector E. Goicoechea, Roberta Lima, Fernando S. Buezas, Rubens Sampaio
Summary: In this paper, a comprehensive continuous Cosserat rod model is developed to study the dynamics of a drill-string. The model can simulate the 3-D dynamics of the system, including lateral, axial and torsional motion, and includes damping effects and a velocity-independent bit-rock interaction formulation. The study compares the model's predictions with two other models and finds divergences in the signals obtained with the Cosserat model, indicating that the new continuous approach can capture aspects of the dynamics that cannot be modeled with low-dimensional representations. The study also evaluates the drilling efficiency and finds that axial oscillations have a positive effect on drilling performance, while torsional stick-slip has a negative effect.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Junzeng He, Dong Jiang, Dahai Zhang, Zhenhuan Tang, Qingguo Fei
Summary: An adaptive Gaussian process model-based model updating method for rotor system is proposed in this study, which utilizes unbalance responses data and multi-channel data fusion to construct the objective function of model updating, effectively reducing the computation cost of repeated finite element calculation. Experimental results show that the proposed method has good accuracy and feasibility.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Ju-Hyok Kim, Jong-Hyok Ri, Hyok Jang, Chol-Ung Choe
Summary: This article introduces the centrifugal pendulum vibration absorber and the significant role of geometric nonlinear damping in reducing torsional vibrations in machines. The research findings suggest that geometric nonlinear damping can effectively eliminate multistability and hysteresis in steady states.
JOURNAL OF SOUND AND VIBRATION
(2024)
Article
Acoustics
Zaiwei Liu, Bin Lin, Xiaohu Liang, Xiaokang Ma, Yangfan Wan
Summary: This paper presents a combined semi-analytical finite element (SAFE) and perfectly matched layer method for accurately predicting the dispersion, attenuation, and polarization modes of surface acoustic waves (SAWs) in materials. The method is validated by comparing the simulated results with exact three-dimensional elasticity theory-based solutions, and the effects of material anisotropy and residual stress on SAWs are discussed. The method is also applied to practical examples and the differences and similarities of two common acoustoelastic theories are discussed.
JOURNAL OF SOUND AND VIBRATION
(2024)
