Dynamic Characteristics Analysis of Axle Box Spring by FEM

2013 ◽  
Vol 712-715 ◽  
pp. 1535-1540
Author(s):  
Li Liu ◽  
Wei Hua Zhang ◽  
Dong Li Song
Keyword(s):  
Dynamic Characteristics ◽  
Dynamic Stiffness ◽  
Dynamic Performance ◽  
Excitation Frequency ◽  
Railway Vehicle ◽  
Helical Spring ◽  
Working Stress ◽  
Characteristics Analysis ◽  
In Series ◽  
Spring Method

Axle box spring of railway vehicle is the structure of helical spring in series with rubber pad to reduce working stress of helical spring and absorb high-frequency vibration. Rubber pad model was built. Static and dynamic characteristics were researched in axial and radial directions. The results show that the static stiffness of rubber pad decreases with the increase of radial displacement and increases distinctly with the increase of the amount of compression; The dynamic stiffness of rubber pad increases with the decrease of the excitation force in the case of the same excitation frequency and decreases with the decrease of the frequency in the case of the same excitation displacement. Axle box spring method was established and the amplitude-frequency curve of dynamic stiffness of the spring was presented. The results provide a theoretical basis to research the dynamic performance of railway vehicle.

Design and structural performance measurements of a novel multi-cantilever foil bearing

2014 ◽  
Vol 229 (10) ◽  
pp. 1830-1838 ◽  
Author(s):  
Kai Feng ◽  
Xueyuan Zhao ◽  
Zhiyang Guo
Keyword(s):  
Dynamic Characteristics ◽  
Dynamic Load ◽  
Dynamic Stiffness ◽  
Excitation Frequency ◽  
Viscous Damping ◽  
Equivalent Viscous Damping ◽  
Foil Bearing ◽  
Load Tests ◽  
Stiffness And Damping ◽  
Motion Amplitude

With increasing need for high-speed, high-temperature, and oil-free turbomachinery, gas foil bearings (GFBs) have been considered to be the best substitutes for traditional oil-lubricated bearings. A multi-cantilever foil bearing (MCFB), a novel GFB with multi-cantilever foil strips serving as the compliant underlying structure, was designed, fabricated, and tested. A series of static and dynamic load tests were conducted to measure the structural stiffness and equivalent viscous damping of the prototype MCFB. Experiments of static load versus deflection showed that the proposed bearing has a large mechanical energy dissipation capability and a pronounced nonlinear static stiffness that can prevents overly large motion amplitude of journal. Dynamic load tests evaluated the influence of motion amplitude, loading orientation and misalignment on the dynamic stiffness and equivalent viscous damping with respect to excitation frequency. The test results demonstrated that the dynamic stiffness and damping are strongly dependent on the excitation frequency. Three motion amplitudes were applied to the bearing housing to investigate the effects of motion amplitude on the dynamic characteristics. It is noted that the bearing dynamic stiffness and damping decreases with incrementally increasing motion amplitudes. A high level of misalignment can lead to larger static and dynamic bearing stiffness as well as to larger equivalent viscous damping. With dynamic loads applied to two orientations in the bearing midplane separately, the dynamic stiffness increases rapidly and the equivalent viscous damping declines slightly. These results indicate that the loading orientation is a non-negligible factor on the dynamic characteristics of MCFBs.

Structural Simulation and Strength Analysis for Trailer Bogie Frame of High-Speed Train Based on CATIA and ANSYS Workbench

2020 ◽  
Vol 13 (3) ◽  
pp. 266-279
Author(s):  
Junguo Wang ◽  
Minqiang Ren ◽  
Rui Sun ◽  
Yang Yang ◽  
Yongxiang Zhao
Keyword(s):  
Dynamic Characteristics ◽  
High Speed ◽  
Structural Strength ◽  
Dynamic Performance ◽  
Static Strength ◽  
Railway Vehicle ◽  
Strength Analysis ◽  
Design Standards ◽  
Bogie Frame ◽  
Ansys Workbench

Background: As a key component of the rail transit vehicle, the railway bogie greatly affects the dynamic performance, reliability, and safety of the high-speed rail vehicle. In this paper, the structural strength of a typical trailer bogie frame is evaluated and its strength and dynamic requirements are verified. In addition, various patents on bogie structural strength have also been discussed in this paper. Objective: The study aimed to evaluate and verify the rationality of the bogie frame structure design with static strength and dynamic characteristics. Methods: A three-dimensional model of the trailer bogie frame was built by CATIA V5, and then, a finite element model of the frame was analyzed by ANSYS Workbench. Bogie frame loads, static strengths and dynamic characteristics of the frame under different conditions (straight, curve, braking and abnormal) were calculated based on its strength and design standards. Results: According to the requirement stress and dynamics standard, the maximum stress of the bogie frame was observed to be in the allowable stress value of the frame material, and the dynamic performance of the bogie model meets the design standards. Conclusion: The structural strength of the proposed bogie frame is reasonable, and the static strength and dynamic characteristics of the proposed bogie model are in accordance with the design requirements of the railway vehicle.

Analysis of dynamic characteristics of spiral groove liquid film seal under thermal–fluid–solid coupling

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Bo Yu ◽  
Muming Hao ◽  
Sun Xinhui ◽  
Zengli Wang ◽  
Liu Fuyu ◽  
...  
Keyword(s):  
Steady State ◽  
Liquid Film ◽  
Dynamic Characteristics ◽  
Dynamic Stiffness ◽  
Dynamic Performance ◽  
Analysis Model ◽  
Spiral Groove ◽  
Content Type ◽  
Sealing Performance ◽  
Stiffness And Damping

Purpose The purpose of this paper is to investigate the dynamic characteristics of spiral groove liquid film seal under the effect of thermal–fluid–solid coupling. Design/methodology/approach The dynamic analysis model of spiral groove liquid film seal under the effect of thermal–fluid–solid coupling was established by perturbation method. The steady-state and perturbation Reynolds equations were solved, and the steady-state sealing performance and dynamic characteristic coefficients of the liquid film were obtained. Findings Compared with the liquid film without coupling method, a divergent seal gap is formed between the seal rings under the effect of thermal–fluid–solid coupling, the minimum liquid film thickness decreases, the dynamic stiffness and damping coefficients of the liquid film are increased and the thermoelastic deformation of the end-face improves the dynamic performance of the liquid film seal. Originality/value The dynamic characteristics of the spiral groove liquid film seal under the effect of thermal–fluid–solid coupling are studied, which provides a theoretical reference for optimizing the dynamic performance of the non-contacting liquid film seal.

Experimental Analysis of the Dynamic Characteristics of a Foil Thrust Bearing

2014 ◽  
Author(s):  
Franck Balducchi ◽  
Mihai Arghir ◽  
Romain Gauthier
Keyword(s):  
Dynamic Characteristics ◽  
Experimental Analysis ◽  
Dynamic Models ◽  
Thrust Bearing ◽  
Dynamic Stiffness ◽  
Excitation Frequency ◽  
Test Rig ◽  
Equivalent Damping ◽  
Start Up ◽  
Foil Thrust Bearing

The paper deals with the experimental analysis of the dynamic characteristics of a foil thrust bearing (FTB) designed following the specifications given by NASA in 2009. The start-up characteristics of the same foil bearing were investigated in a recently published paper. The test rig used for start-up measurements was adapted for dynamic measurements. The paper presents the test rig in detail as well as its identified dynamic models. Measurements of the dynamic characteristics of the bump foil structure were performed for static loads comprised between 30 N and 150 N while measurements for the FTB were performed at 35 krpm for 30 N, 60 N and 90 N. Excitation frequencies were comprised between 150 Hz and 750 Hz. Results showed that the dynamic stiffness of the FTB increase with excitation frequency while the equivalent damping decreases. Both stiffness and damping increase with the static load but are smaller at 35 krpm compared to 0 rpm.

Experimental Analysis of the Dynamic Characteristics of a Foil Thrust Bearing

2015 ◽  
Vol 137 (2) ◽  
Author(s):  
Franck Balducchi ◽  
Mihai Arghir ◽  
Romain Gauthier
Keyword(s):  
Dynamic Characteristics ◽  
Experimental Analysis ◽  
Gas Turbines ◽  
Thrust Bearing ◽  
Dynamic Stiffness ◽  
Excitation Frequency ◽  
Equivalent Damping ◽  
Start Up ◽  
And Performance ◽  
Foil Thrust Bearing

This paper deals with the experimental analysis of the dynamic characteristics of a foil thrust bearing (FTB) designed according to specifications given by NASA scientists in 2009 (Dykas et al., 2009, “Design, Fabrication, and Performance of Foil Gas Thrust Bearings for Microturbomachinery Applications,” ASME J. Eng. Gas Turbines Power, 131(1), p. 012301). The present work details the new configuration of the same test rig that was used to test start-up characteristics of the aforementioned bearing (Balducchi et al., 2013, “Experimental Analysis of the Start-Up Torque of a Mildly Loaded Foil Thrust Bearing,” ASME J. Tribol., 135(3), p. 031703). The rig has been reconfigured to test dynamic characteristics. The dynamic characteristics of the bump foil structure were measured for static loads comprised between 30 N and 150 N while measurements for the FTB were performed at 35 krpm for 30 N, 60 N, and 90 N. Excitation frequencies were comprised between 150 Hz and 750 Hz. Results showed that the dynamic stiffness of the FTB increase with excitation frequency while the equivalent damping decreases. Both stiffness and damping increase with the static load but are smaller at 35 krpm compared to 0 rpm.

Experimental Analysis of Dynamic Characteristic for Automatic Tensioner

2014 ◽  
Vol 915-916 ◽  
pp. 49-52
Author(s):  
Xiang Kun Zeng
Keyword(s):  
Dynamic Characteristics ◽  
Experimental Analysis ◽  
Angular Displacement ◽  
Dynamic Stiffness ◽  
Excitation Frequency ◽  
Excitation Amplitude ◽  
Loss Angle ◽  
Load Torque ◽  
Dynamic Performances ◽  
Stiffness Loss

Experimental method and parameters to investigate the dynamic performances of an automatic tensioner are discussed. Parameters to evaluate the dynamic performances of a tensioner include dynamic stiffness, loss angle and equivalent viscous coefficient. Dynamic stiffness and loss angle can be measured directly, and the equivalent viscous coefficient can be calculated by torque-angular displacement loop which identified with the parameters including dynamic stiffness, loss angle, pre-load torque, pre-load angular displacement, excitation amplitude and excitation frequency. In this paper, the influences of excitation amplitude, excitation frequency and pre-load torque on the dynamic characteristics of tensioner are measured and investigated.

scholarly journals Effect of Dynamic Stiffness of Fasteners on Vibration and Acoustic Radiation of a Ballastless Track

2021 ◽  
Author(s):  
hanwen xu ◽  
jian han ◽  
xinbiao xiao ◽  
xiaolong liu ◽  
moukai liu ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Dynamic Property ◽  
Acoustic Radiation ◽  
Dynamic Stiffness ◽  
Excitation Frequency ◽  
Vertical Direction ◽  
Coupled System ◽  
Fe Method ◽  
Ballastless Track ◽  
Wheel Rolling

Abstract A new model for a single wheel rolling over a metro ballastless track is developed. It is used to carry out the analysis on the effect of dynamic characteristics of fastener on the vibration and noise radiation of the wheel and the track in the vertical direction, under the excitation of the wheel/rail uneven surfaces in detail. In this analysis, a rail is modeled as a Timoshenko beam resting on discrete rubber booted short sleepers, and the sleepers are connected with the slab through linear springs and damping units, the slab is modeled by using the FE method, the fastener is characterized by using the Poynting-Thomson model which takes into account that the stiffness and dumping of the fasteners vary with vibration frequency in their service. The dynamic characteristics of the fastener include the variation of its stiffness and damping with frequency. The analysis considers that the fastener dynamic stiffness increases with the excitation frequency while its damping decreases. The vibration and acoustic radiation of the wheel/track is, to varying degree, affected by the dynamic property of the fastener. The vibration and acoustic radiation of the sleeper and the slab is greatly affected by the dynamic property of the fastener. But the effect of the total noise level of the wheel and the track by the dynamic property of the fastener is not so large because the wheel and rail noise is dominant in the whole analyzed system. These conclusions have certain reference values for the study of the vibration and noise reduction measures of the wheel and track coupled system using the fastening characteristic.

scholarly journals An Investigation into the Modeling Methodology of the Coil Spring

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Liangcheng Dai ◽  
Maoru Chi ◽  
Hongxing Gao ◽  
Jianfeng Sun
Keyword(s):  
Mass Distribution ◽  
Dynamic Characteristics ◽  
Dynamic Stiffness ◽  
Railway Vehicle ◽  
Spring Model ◽  
Coil Spring ◽  
Railway Vehicles ◽  
Equivalent Models ◽  
Laboratory Test Results ◽  
Exciting Frequency

The coil spring is an important element in the suspension system of railway vehicles, and its structural vibration caused by the mass distribution can deteriorate the dynamic performance of the vehicle. However, the coil spring is usually modelled as a simple linear force element without considering the dynamic characteristics in multibody dynamic simulations of railway vehicles. To integrate the dynamic characteristics of the coil spring into the simulation, three equivalent dynamic models of the coil spring are established by treating the coil spring as multimass spring series, Timoshenko beam, and flexible spring, respectively. The frequency-sweep method is applied to obtain the dynamic response of the proposed models of coil spring, and the accuracy of the models’ results has been compared and verified by the laboratory test. Results show that all of these three equivalent models can reflect the influence of the spring mass distribution on its dynamic responses. Compared with the mass-spring series and beam element equivalent models, the flexible spring model can better reflect the dynamic stiffness and stress of the coil spring changing with the exciting frequency. Thus, the flexible spring model proposed in this paper is more applicable to railway vehicle system dynamics and the fatigue analysis.

scholarly journals Study on Dynamic Characteristics of Aerostatic Bearing with Elastic Equalizing Pressure Groove

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Xiao-long Zhao ◽  
Hao Dong ◽  
Zhou Fang ◽  
Deng-di Chen ◽  
Jun-an Zhang
Keyword(s):  
Dynamic Characteristics ◽  
Dynamic Stiffness ◽  
Dynamic Performance ◽  
Coupling Model ◽  
Damping Coefficient ◽  
Aerostatic Bearing ◽  
Equivalent Damping ◽  
New Type ◽  
Equivalent Damping Coefficient ◽  
Control Equation

Microvibration has an important influence on the dynamic performance of aerostatic bearings. Dynamic stiffness and equivalent damping coefficient are the main indexes to evaluate the dynamic characteristics of the aerostatic bearing. In order to study the dynamic characteristics of a new type of aerostatic bearing with the elastic equalizing pressure groove (EEPG), the dynamic characteristics of the new type of bearing are studied by theoretical calculation and experiment. First, the dynamic gas-solid coupling control equation is established. Then, the steady term and the perturbation term are decomposed by the perturbation method. By solving the coupling model, the dynamic characteristics of the bearing are calculated and analyzed. The calculation results show that the perturbation frequency has a significant effect on the dynamic stiffness and equivalent damping coefficient of the aerostatic bearing with EEPG. The dynamic stiffness increases with the increase of frequency, and the equivalent damping coefficient decreases with the increase of frequency. The experimental results are basically the same with the theoretical results, which effectively verify the correctness of the theoretical analysis.

scholarly journals Simulation Research on Dynamic Characteristics of Hydraulic Mount

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Yanhua Liu ◽  
Xin Guan ◽  
Pingping Lu ◽  
Rui Guo
Keyword(s):  
Dynamic Characteristics ◽  
Mechanical Model ◽  
Structural Parameters ◽  
Dynamic Stiffness ◽  
Dynamic Performance ◽  
Evaluation Index ◽  
Loss Angle ◽  
Element Analysis ◽  
Nonlinear Mechanical ◽  
Performance Evaluation Index

AbstractAt present, research on hydraulic mounts has mainly focused on the prediction of the dynamic stiffness and loss angle. Compared to the traditional finite element analysis method, the programming method can be used to analyze hydraulic mounts for a rapid and accurate understanding of the influence of the different mounting parameters on the dynamic stiffness and loss angle. The aims of this study were to investigate the nonlinear dynamic characteristics of a hydraulic mount, and to identify the parameters that affect the dynamic stiffness and loss angle using MATLAB software programs to obtain the influence curves of the parameters, so as to use suitable parameters as the basis for vibration analysis. A nonlinear mechanical model of a hydraulic mount was established according to the basic principles of fluid dynamics. The dynamic stiffness and loss angle of the dimensionless expression were proposed. A numerical calculation method for the dynamic performance evaluation index of the hydraulic mount was derived. A one-to-one correspondence was established between the structural parameters and peak frequency of the evaluation index. The accuracy and applicability of the mechanical model were verified by the test results. The results demonstrated the accuracy of the nonlinear mechanical model of the hydraulic mount, and the vehicle driving comfort was greatly improved by the optimization of the structural parameters.

Sign in / Sign up

Export Citation Format

Share Document