scholarly journals The Planar Wide-Frequency Vibration Characteristics of Heavy-Load Radial Tires

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Hongjie Cheng ◽  
Lei Gao ◽  
Zhihao Liu ◽  
Qinhe Gao ◽  
Xiuyu Liu
Keyword(s):  
Transfer Functions ◽  
Structural Parameters ◽  
Vibration Characteristics ◽  
Flexible Beam ◽  
Tire Model ◽  
Large Aspect Ratio ◽  
Heavy Load ◽  
Cross Sectional ◽  
Radial Tire ◽  
Damping Coefficients

This paper investigates the planar wide-frequency vibration characteristics of heavy-load radial tires with a large aspect ratio. A proposed tire model with a piecewise flexible beam on an elastic foundation is investigated and validated using experimental modal analysis and theoretical modeling method. The reproducibility of frequency response functions below 400 Hz is discussed. The experimental modal analysis particularly assesses the coupling of features across the circumferential and cross-sectional directions of heavy-load radial tire carcass. Piecewise circumferential modal characteristics were investigated experimentally, leading to the suggestion of a piecewise flexible beam on an elastic tire foundation. Using a genetic algorithm (GA), the structural parameters EI, ρ A , and kr and damping coefficients η and cr for the proposed tire model are identified, and the piecewise transfer functions and the planar transfer functions for a heavy-load radial tire are compared with planar hammer test. Experimental and theoretical results show the following: (1) the sectional vibration characteristics for a heavy-load radial tire with a large aspect ratio result from the cross-sectional vibration of the tire carcass; (2) the piecewise transfer function is mainly influenced by the circumferential vibration of the flexible carcass, and this is consistent with a model where a flexible beam is placed on an elastic tire foundation; (3) the analytical transfer functions calculated for the proposed tire model, drawing on the identified structural parameters and damping coefficients, agree well with the experimental results.

Parametric analysis of in-plane rigid-elastic coupled non-contact tire model for heavily loaded radial tire

2018 ◽  
Vol 233 (1) ◽  
pp. 91-107
Author(s):  
Zhihao Liu ◽  
Qinhe Gao
Keyword(s):  
Transfer Function ◽  
Parametric Analysis ◽  
Transfer Functions ◽  
Structural Parameters ◽  
Mass Matrix ◽  
Flexible Beam ◽  
Vibration Characteristic ◽  
Tire Model ◽  
Modal Parameter ◽  
Radial Tire

Parametric analysis of in-plane vibration characteristic for unloaded heavily loaded radial tire is put forward and researched utilizing in-plane rigid-elastic coupled model. Coupled vibration characteristic between the flexible tread and circumferential sidewall is investigated with theoretical modeling and experimental modal method. In-plane analytical vibration feature is modeled with flexible beam on modified elastic foundation tire model. The rigid-elastic coupled tire model is derived with finite difference method and stiffness matrix and mass matrix are presented analytically with the geometrical and structural parameters. Structural parameters identification is implemented with genetic algorithm based on in-plane experimental modal parameter. The in-plane transfer functions with different structural parameters are compared and the parametric effect of structural parameters on in-plane transfer function is discussed. Experimental and theoretical result shows that the in-plane rigid-elastic coupled tire model can achieve the higher precision on predicting the transfer function and vibration feature of heavily loaded tire within the frequency band of 300 Hz.

scholarly journals Development of the Flexible Ring on an Elastic Continuous Foundation Tire Model for Planar Vibration of the Heavy Load Radial Tire

2018 ◽  
Vol 8 (11) ◽  
pp. 2064
Author(s):  
Zhihao Liu ◽  
Qinhe Gao ◽  
Hailong Niu
Keyword(s):  
Structural Parameters ◽  
Kinematic Characteristic ◽  
Vibration Characteristic ◽  
Tire Model ◽  
Inflation Pressure ◽  
Heavy Load ◽  
Coupling Vibration ◽  
Radial Tire ◽  
Planar Vibration ◽  
Flexible Ring

This paper investigates the planar vibration characteristic of heavy load radial tires with a large flat ratio. A proposed tire model with a flexible ring on an elastic continuous foundation is investigated utilizing kinematic modeling and experimental modal analysis. Planar coupling deformation of the radial and tangential direction is considered to enrich the kinematic characteristic of the flexible belt and the continuous sidewall; a flexible ring on an elastic continuous foundation tire model is proposed to investigate the coupling vibration characteristic between the flexible belt and the continuous sidewall. In-extensibility assumption is utilized to simplify the proposed tire model and the planar vibration modal features of the heavy load radial tire are discussed. The variation of the inflation pressure on the radial and tangential stiffness of the sidewall spring model is enriched into the flexible ring on an elastic continuous foundation tire model to extend the modal prediction of the tires with a different inflation pressure. Taking the relative error between the experimental and analytical modal resonance frequency of the tested tire with a different inflation pressure as the object value, structural parameters of the proposed tire model are identified by a backward genetic algorithm. Experimental and theoretical results show that: the planar coupling vibration characteristic of the heavy load radial tire can be predicted precisely with the flexible ring on an elastic continuous foundation tire model; meanwhile, considering the linear variations of the radial and tangential sidewall stiffness due to the inflation pressure, the proposed tire model can be extended to analyze the vibration characteristic of the heavy load radial tire with a different inflation pressure.

In-plane vibration response of time and frequency domain with rigid-elastic coupled tire model with continuous sidewall

2017 ◽  
Vol 232 (4) ◽  
pp. 429-445 ◽  
Author(s):  
Zhihao Liu ◽  
Qinhe Gao
Keyword(s):  
Transfer Function ◽  
Frequency Domain ◽  
Frequency Band ◽  
Structural Parameters ◽  
Bending Stiffness ◽  
Flexible Beam ◽  
Tire Model ◽  
Continuous Beam ◽  
Radial Tire ◽  
Plane Vibration

The in-plane vibration characteristic of time and frequency domain for heavy-loaded radial tire with a larger flat ratio (close to 1) is researched by utilizing the rigid-elastic coupled tire model with continuous sidewall. The sidewall bending stiffness is considered and the flexible beam on the elastic continuous beam tire model is proposed and investigated analytically to simulate the in-plane vibration of the heavy-loaded radial tire within more wider frequency band. The rigid-elastic coupled tire model is derived with finite difference method and the analytical stiffness matrix; mass matrix is formed based on the geometrical and structural parameters of heavy-loaded radial tire. Structural parameters are identified utilizing genetic algorithm based on the error between the analytical and experimental modal frequency. In-plane frequency domain transfer function and time domain dynamics response of heavy-loaded radial tire is investigated and compared with the experimental result. Experimental and theoretical results show that in-plane rigid-elastic coupled tire model with sidewall bending stiffness can be used to precisely predict the transfer function and vibration feature within the frequency band of 300 Hz, compared with the tire model with the distributed independent sidewall element. The flexible beam on the elastic continuous beam tire model and rigid-elastic coupled tire model with continuous sidewall can be extended to the dynamic analysis of the tire with larger flat ratio or the tire under the impulsive loading conditions.

Development and parameter identification of the flexible beam on elastic continuous tire model for a heavy-loaded radial tire

2018 ◽  
Vol 24 (22) ◽  
pp. 5233-5248 ◽  
Author(s):  
Zhihao Liu ◽  
Qinhe Gao
Keyword(s):  
Parameter Identification ◽  
Structural Parameters ◽  
Flexible Beam ◽  
Vibration Modes ◽  
Tire Model ◽  
Continuous Beam ◽  
Inflation Pressure ◽  
Bending Vibration ◽  
Radial Tire ◽  
Pressure Sensitive

Experimental modal analysis, dynamic modeling, and parameter identification were employed to investigate the flexible beam tire model for a heavy-loaded radial tire. The in-plane bending vibration of the flexible tread is researched with the flexible beam tire model. The coupled vibration equation of the flexible tread and continuous sidewall is modeled with a flexible beam on elastic continuous beam tire model. The nonlinear sidewall dynamics sensitive to the inflation pressure is obtained. The coupled modal features of a heavy-loaded radial tire are presented experimentally for different inflation pressures. Structural parameters are identified by a backward genetic algorithm based on the error between the experimental and analytical modal resonant frequency for different inflation pressures. Experimental and theoretical results show that the flexible beam on elastic continuous beam tire model developed for the heavy-loaded radial tire with a larger flat ratio can achieve higher precision in predicting the in-plane vibration modes of the heavy-loaded radial tire. It can be extended to analyze the vibration modes of the heavy-loaded radial tire with different inflation pressures by taking the inflation pressure-sensitive radial stiffness of the sidewall into consideration.

In-Plane Flexible Beam on Elastic Foundation With Combined Sidewall Stiffness Tire Model for Heavy-Loaded Off-Road Tire

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Zhihao Liu ◽  
Qinhe Gao ◽  
Hailong Niu
Keyword(s):  
Elastic Foundation ◽  
Structural Parameters ◽  
Flexible Beam ◽  
Tire Model ◽  
Structural Stiffness ◽  
Inflation Pressure ◽  
Euler Beam ◽  
Large Section ◽  
Section Ratio ◽  
Beam On Elastic Foundation

Combining the flexible carcass beam and the radial sidewall element, flexible beam on elastic foundation with combined sidewall stiffness tire model is proposed for heavy-loaded off-road tire with a large section ratio. The circumferential vibration of flexible carcass is modeled as Euler beam and the influence of inflation pressure on the circumferential vibration of flexible carcass is investigated with the modal experiment and theoretical modeling. The structural stiffness caused by the sidewall curvature and pretension stiffness caused by the inflation pressure is combined for the radial sidewall element. The influence of the sidewall structural parameters on the combined stiffness of sidewall and modal resonant frequency is researched and discussed. The nonlinear combined stiffness of sidewall is investigated with respect to the radial sidewall deformation. Experimental and theoretical results show that: (1) the combined stiffness of sidewall can character the pretension stiffness caused by inflation pressure and the structural stiffness led by the sidewall curvature and material properties and (2) the combined stiffness of sidewall is nonlinear with respect to the radial sidewall deformation, which is prominent with high inflation pressure. Taking the flexibility characteristic of tire carcass and the nonlinear stiffness of sidewall into consideration, flexible beam on elastic foundation with combined sidewall stiffness tire model is suitable for the heavy-loaded off-road tire with a large section ratio or tires under impulsive loading and large deformation.

An Experimental Study of Tendon Vibration Control System for Flexible Space Structures

1991 ◽  
Author(s):  
Yoshisada Murotsu ◽  
Hiroshi Okubo ◽  
Kei Senda
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Vibration Control ◽  
Transfer Functions ◽  
Mimo Systems ◽  
Experimental System ◽  
Space Structures ◽  
Flexible Beam ◽  
Tendon Vibration ◽  
Large Space

Abstract The idea of a tendon vibration control system for a beam-like flexible space structure has been proposed. To verify the feasibility of the concept, an experimental tendon control system has been constructed for the vibration control of a flexible beam simulating Large Space Structures (LSS). This paper discusses modeling, identification, actuator disposition, and controller design for the experimental system. First, a mathematical model of the whole system of the beam and tendon actuator is developed through a finite element method (FEM). Second, to obtain an accurate mathematical model for designing a controller, unknown characteristic parameters are estimated by using an output error method. The validity of the proposed identification scheme is demonstrated by good agreement between the transfer functions of the experimental system and an identified model. Then, disposition of actuators is discussed by using the modal cost analysis. Finally, controllers are designed for SISO and MIMO systems. The feasibility of the proposed controller is verified through numerical simulation and hardware experiments.

Hydrodynamic coefficients of a floater near a partially reflecting seawall in the presence of an array of caisson blocks

2021 ◽  
pp. 1-23
Author(s):  
K G Vijay ◽  
Santanu Koley ◽  
Kshma Trivedi ◽  
Chandra Shekhar Nishad
Keyword(s):  
Wave Scattering ◽  
Structural Parameters ◽  
Wave Force ◽  
Vertical Force ◽  
Hydrodynamic Coefficients ◽  
Floating Structure ◽  
Surface Gravity Wave ◽  
Damping Coefficients ◽  
Half Wavelength ◽  
Scattering And Radiation

Abstract In the present study, surface gravity wave scattering and radiation by a freely floating rectangular buoy placed near a partially reflecting seawall and in the presence of an array of caisson blocks are analyzed. Various hydrodynamic parameters related to the wave scattering and radiation, such as the added mass and radiation damping coefficients, correspond to sway, heave and roll motions of the floating buoy, horizontal force, vertical force and moment acting on the floating structure, and horizontal wave force acting on the partially reflecting seawall are studied for a variety of wave and structural parameters. The study reveals that the resonating pattern in various hydrodynamic coefficients occurs for moderate values of the wavenumber. Further, when the distance between the floater and the sidewall is an integral time of half wavelength, the resonating behavior in the sway, heave and roll added masses, and associated damping coefficients appears, and the aforementioned hydrodynamic coefficients change rapidly around this zone. These resonance phenomena can be diminished significantly with appropriate positioning of the floater with respect to the sidewall and in the presence of partially reflecting seawall.

Volume change of the ocular lens during accommodation

2007 ◽  
Vol 293 (2) ◽  
pp. C797-C804 ◽  
Author(s):  
R. Gerometta ◽  
A. C. Zamudio ◽  
D. P. Escobar ◽  
O. A. Candia
Keyword(s):  
Structural Parameters ◽  
Center Of Mass ◽  
Physiological Solution ◽  
Volume Determination ◽  
Cross Sectional ◽  
Lens Fibers ◽  
Human Lenses ◽  
Lens Surface ◽  
Shape Changes ◽  
Anterior Posterior

During accommodation, mammalian lenses change shape from a rounder configuration (near focusing) to a flatter one (distance focusing). Thus the lens must have the capacity to change its volume, capsular surface area, or both. Because lens topology is similar to a torus, we developed an approach that allows volume determination from the lens cross-sectional area (CSA). The CSA was obtained from photographs taken perpendicularly to the lenticular anterior-posterior (A-P) axis and computed with software. We calculated the volume of isolated bovine lenses in conditions simulating accommodation by forcing shape changes with a custom-built stretching device in which the ciliary body-zonulae-lens complex (CB-Z-L) was placed. Two measurements were taken (CSA and center of mass) to calculate volume. Mechanically stretching the CB-Z-L increased the equatorial length and decreased the A-P length, CSA, and lens volume. The control parameters were restored when the lenses were stretched and relaxed in an aqueous physiological solution, but not when submerged in oil, a condition with which fluid leaves the lens and does not reenter. This suggests that changes in lens CSA previously observed in humans could have resulted from fluid movement out of the lens. Thus accommodation may involve changes not only in capsular surface but also in volume. Furthermore, we calculated theoretical volume changes during accommodation in models of human lenses using published structural parameters. In conclusion, we suggest that impediments to fluid flow between the aquaporin-rich lens fibers and the lens surface could contribute to the aging-related loss of accommodative power.

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