Simulation of Bus Ride Comfort under the Excitation of Road Irregularity

2012 ◽  
Vol 510 ◽  
pp. 249-254 ◽  
Author(s):  
Jin Feng ◽  
Yuan Hua Chen

Bus vibration is studied by the finite element method (FEM) base on bus structure model. The bus mathematical model of vertical vibration is established and the vibration response variables were deduced with the modal analysis method. The finite element (FE) model is established and decoupled. The transformational relation between spatial frequency displacement power spectral density (PSD) and temporal frequency displacement PSD and the sampling characteristics of the road irregularity PSD in numerical computation are discussed. Road irregularity load is modeled in software. The FE model is solved using modal analysis method and the acceleration PSD of each keypoint can be gained. Finally, a road test experiment is carried on to verify the simulation results. The example indicated that study on vehicle ride comford by FEM has instructive meaning.

2013 ◽  
Vol 791-793 ◽  
pp. 718-721
Author(s):  
Man Man Xu ◽  
Yu Li ◽  
Sai Nan Xie ◽  
Qing Hua Chen

To analyse the road-header rack and pinion by using the finite element analysis software COSMOS/WORKS. Compared to the traditional analytic calculation and numerical analysis method, it is more intuitively get 28 ° pressure angle spur gear rack meshing stress and strain distribution, which can rack and pinion improvements designed to provide scientific reference.


2017 ◽  
Vol 7 ◽  
pp. 219-223
Author(s):  
Beril Demir Karamanli ◽  
Hülya Kılıçoğlu ◽  
Armagan Fatih Karamanli

Aims The aim of this study is to evaluate the effects of the chincup appliance used in the treatment of Class III malocclusions, not only on the mandible or temporomandibular joint (TMJ) but also on all the craniofacial structures. Materials and Methods Chincup simulation was performed on a three-dimensional finite element (FE) model. 1000 g (500 g per side) force was applied in the direction of chin-condyle head. Nonlinear FE analysis was used as the numerical analysis method. Results By the application of chincup, stresses were distributed not only on TMJ or mandible but also on the circummaxillary sutures and other craniofacial structures. Conclusions Clinical changes obtained by chincup treatment in Class III malocclusions are not limited by only mandible. It was seen that also further structures were affected.


Author(s):  
Xiaofeng Yang ◽  
Long Yan ◽  
Yujie Shen ◽  
Hongchang Li ◽  
Yanling Liu

Inerter, a new type of mass element, can increase the inertia of motion between two endpoints. In order to study the dynamic inertia effect of inerter–spring–damper suspension for heavy vehicle on ride comfort and road friendliness, the inerter–spring–damper suspension is applied and its mechanism is studied. This paper establishes a half vehicle model of inerter–spring–damper suspension for heavy vehicle. The parameters of inerter–spring–damper suspension for heavy vehicle are optimized by multi-objective genetic algorithm and system simulations are carried out. The parametric influence of different spring stiffness, damping coefficient, inertance, and load on suspension performance is also studied. The simulation results demonstrate that the centroid acceleration and pitch angular acceleration are improved by 24.90% and 23.54%, respectively, and the comprehensive road damage coefficient is reduced by 4.05%. The results illustrate that the inerter–spring–damper suspension can decrease the vertical vibration of vehicle suspension especially in low frequency and reduce the road damage. The analyses of suspension parameters perturbation reveal their different effect laws of the different wheels on vehicle ride comfort and road friendliness, which provide a theoretical basis for setting parameters of inerter–spring–damper suspension.


2020 ◽  
Vol 10 (22) ◽  
pp. 8167
Author(s):  
Mădălina Dumitriu ◽  
Dragoș Ionuț Stănică

The theoretical research on means to reduce the vertical vibrations and improve the ride comfort of the railway vehicle relies on a mechanical model obtained from the simplified representation of the vehicle, while considering the important factors and elements affecting the vibration behaviour of the carbody. One of these elements is the anti-yaw damper, mounted longitudinally, between the bogie and the vehicle carbody. The anti-yaw damper reduces the lateral vibrations and inhibits the yaw motion of the vehicle, a reason for which this element is not usually introduced in the vehicle model when studying the vertical vibrations. Nevertheless, due to the position of the clamping points of the anti-yaw damper onto the carbody and the bogie, the damping force is generated not only in the yawing direction but also in the vertical and longitudinal directions. These forces act upon the vehicle carbody, impacting its vertical vibration behaviour. The paper analyzes the effect of the anti-winding damper on the vertical vibrations of the railway vehicle carbody and the ride comfort, based on the results derived from the numerical simulations. They highlight the influence of the damping, stiffness and the damper mounting angle on the power spectral density of the carbody vertical acceleration and the ride comfort index.


Author(s):  
Lassaad Ben Fekih ◽  
Georges Kouroussis ◽  
David Wattiaux ◽  
Olivier Verlinden ◽  
Christophe De Fruytier

An approach is proposed to identify the modal properties of a subsystem made up of an arbitrary chosen inner module of embedded space equipment. An experimental modal analysis was carried out along the equipment transverse direction with references taken onto its outer housing. In parallel, a numerical model using the finite element (FE) method was developed to correlate with the measured results. A static Guyan reduction has led to a set of master degrees of freedom in which the experimental mode shapes were expanded. An updating technique consisting in minimizing the dynamic residual induced by the FE model and the measurements has been investigated. A last verification has consisted in solving the numeric model composed of the new mass and stiffness matrices obtained by means of a minimization of the error in the constitutive equation method.


2021 ◽  
Vol 2 (3) ◽  
Author(s):  
Kehui Ma ◽  
Yongguo Zhang ◽  
Xü Zhen

The road input model is very important in the analysis of vehicle ride comfort and handling stability. Based on the analysis of the relationship between the spatial frequency power spectral density and the time power spectral density of the road, the road signal generation model is established. The simulation is carried out under different vehicle speeds, and the B and C-level random road time excitation signals are generated. The power spectral density is used to compare the simulation results of the model with the road classification standard. The experimental results show that the results are accurate and can provide reliable excitation signals for vehicle control research.


2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Lu Zhang ◽  
Shaohua Wang ◽  
Peng Guo ◽  
Qunsheng Wang

This paper presents a simulation approach based on the finite element method (FEM) to analyze the wind-induced vibration response of an inspection vehicle for main cables. First, two finite element (FE) models of a suspension bridge and a main cable-inspection vehicle coupled system are established using MIDAS Civil software and ANSYS software, respectively. Second, the mean wind speed distribution characteristics at a bridge site are analyzed, and the wind field is simulated based on the spectral representation method (SRM). Third, a modal analysis and a wind-induced vibration response transient analysis of the suspension bridge FE model are completed. Fourth, the vibration characteristics of the inspection vehicle are analyzed by applying fluctuating wind conditions and main cable vibration displacements in the main cable-inspection vehicle coupled FE model. Finally, based on the ISO2631-1-1997 standard, a vehicle ride comfort evaluation is performed. The results of the suspension bridge FE modal analysis are in good accordance with those of the experimental modal test. The effects of the working height, number of nonworking compressing wheels, and number of nonworking driving wheels during driving are discussed. When the average wind speed is less than 13.3 m/s, the maximum total weighted root mean square acceleration (av) is 0.1646 m/s2 and the vehicle ride comfort level is classified as “not uncomfortable.” This approach provides a foundation for the design and application of inspection vehicles.


2012 ◽  
Vol 19 (5) ◽  
pp. 1051-1059 ◽  
Author(s):  
A. Devin ◽  
P.J. Fanning

Structures include elements designated as load bearing and non-load bearing. While non-load bearing elements, such as facades and internal partitions, are acknowledged to add mass to the system, the structural stiffness and strength is generally attributed to load bearing elements only. This paper investigates the contribution of non-load bearing elements to the dynamic response of a new structure, the Charles Institute, in the grounds of University College Dublin (UCD) Ireland. The vertical vibration response of the first floor and the lateral response at each floor level were recorded at different construction stages. The evolution of the structural response as well as the generation of a finite element (FE) model is discussed. It was found that the addition of the non-load bearing facades increased the first floor natural frequency from 10.7 Hz to 11.4?Hz, a change of approximately +6.5%. Similarly these external facades resulted in the first sway mode having its frequency increased by 6%. The subsequent addition of internal partitions, mechanical services and furnishings resulted in the floor natural frequency reducing to 9.2 Hz. It is concluded that external facades have the net effect of adding stiffness and the effect of internal partitions and furnishings is to add mass. In the context of finite element modelling of structures there is a significant challenge to represent these non-structural elements correctly so as to enable the generation of truly predictive FE models.


2011 ◽  
Vol 250-253 ◽  
pp. 2424-2427 ◽  
Author(s):  
Xin Zhao ◽  
Mai Wu ◽  
Dan Dan Kong ◽  
Shun Wei Chen

Autoclaved lightweight concrete (ALC) block infills are used widely for steel residential building system in China; the authors of this paper brought forward a kind of macro finite element (FE) model of ALC block infills of steel frames on the basis of experimental study. Furthermore the hysteresis model of the strut element of infill was established. At last the validity of the strut element was verified by comparison theory analysis results with experiment ones. The analysis method and theory of this paper can be applied to other kind of infills after being revised properly.


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