The Application of Pseudo-Excitation Method to the Ride Comfort Research of Wheel-Loader

2010 ◽  
Vol 34-35 ◽  
pp. 538-543 ◽  
Author(s):  
Chun Yan Chi ◽  
Si Cheng Qin ◽  
Ding Wen Yu ◽  
Wei Jun Zhang

The wheel-loader is modeled as a linear 12-DOF system in this paper for researching its ride comfort under typical working situations. The pseudo-excitation method is introduced for vibration analysis, which accuracy has been validated. By using this method and taking a certain type of wheel-loader as a representative example, the spectral density of real response of wheel-loader such as the vertical acceleration of driver, the for-and-aft angular acceleration of bucket and the wheel relative dynamic force due to different carrying capacity, speed and the road surface level are obtained. The results offer the theoretical evidence for the farther wheel-loader vibration reduction research.

2009 ◽  
Vol 41 (7) ◽  
pp. 699-711 ◽  
Author(s):  
W. T. Xu ◽  
J. H. Lin ◽  
Y. H. Zhang ◽  
D. Kennedy ◽  
F. W. Williams

2020 ◽  
Vol 23 (15) ◽  
pp. 3263-3277
Author(s):  
Lidong Wang ◽  
Zhihui Zhu ◽  
Pedro Alves Costa ◽  
Yu Bai ◽  
Zhiwu Yu ◽  
...  

A framework is developed in this article to predict the nonstationary random ground vibrations induced by high-speed trains, by combining the pseudo-excitation method with the two-and-a-half-dimensional finite element method. This development contains two steps. First, the power spectral density of the wheel–rail dynamic force is accurately obtained through the combination of the pseudo-excitation method and a vehicle–slab-track–ground theoretical model. Second, the nonstationary random ground vibrations are efficiently solved by combining the pseudo-excitation method and the two-and-a-half-dimensional finite element method, where the power spectral density of the wheel–rail dynamic force obtained in the former step is used to constitute the pseudo-loads. In the numerical examples, the accuracy and efficiency of the proposed approach are validated through the comparison to the fast three-dimensional random method for train–track–soil system developed previously. The results show that the proposed approach can predict the train-induced random ground vibrations with sufficient accuracy and has three-to-five times increase in efficiency in comparison to the fast three-dimensional random method.


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.


Author(s):  
Siyu Zhu ◽  
Tianyu Xiang

The stochastic pseudo excitation method (SPEM), which is based on the principle of pseudo excitation method (PEM), is introduced to represent the randomness of dynamic input in which the amplitude of excitation is adopted as a random variable. Based on the mathematic definition of power spectral density, a physical interpolation of the SPEM is discussed. Even if one random variable is involved in calculation, the effects of the uncertainties are required to be investigated. The SPEM offers a simple but quite effective way to solve the dynamic reliability problem. Through integrating the new algorithm into first-order reliability method (FORM), the dynamic reliability of uncertain structure subjected to random excitation is studied. A linear oscillator with three types of white noise is adopted to verify the SPEM for dynamic reliability of linear random vibration analysis. Also, the accuracy and efficiency of SPEM to handle the multi-degree-of-freedom structure is investigated in this paper.


2020 ◽  
Vol 31 (9) ◽  
pp. 1204-1219
Author(s):  
Jingjuan Zhai ◽  
Linyuan Shang ◽  
Guozhong Zhao

Simultaneous optimization of multiple parameters of an active structural acoustic control system under random force excitation is presented in this article. A method integrating the pseudo excitation method, finite element method, and boundary element method is proposed to analyze the random acoustic radiation. The active structural acoustic control of randomly vibrating structures is developed using the velocity feedback control scheme with the help of the pseudo excitation method. The acoustic design optimization model is proposed, in which the auto power spectral density of sound pressure is taken as the objective function and the placements of actuators/sensors as well as control gains are assigned as design variables. Taking into account the operational efficiency and control cost, the number of actuators/sensors and the total actuation energy are considered as constraints. A simulated annealing algorithm is employed for the optimization problem with discrete and continuous variables coexisting. Numerical examples are given to demonstrate the effectiveness of the proposed methods and the programs, and several key factors on the optimized designs are also discussed.


Author(s):  
Yuefang Wang ◽  
Yan Liu ◽  
Xuejun Wang ◽  
Hongkun Li ◽  
Daren Jiang

Dynamic response of impeller of centrifugal compressor is studied considering pulsating pressure field on blades due to unsteady flow conditions. The aerodynamic forces on the blades are modeled as random load whose spectral characteristics are determined through computational fluid dynamic simulations in the time domain. The dynamical response in the unsteady case is solved as a random vibration problem in the frequency domain which provides useful power spectral density displacement and stress for early stage of impeller design. A semi-open impeller mounted with 19 blades is modeled using three dimensional solid finite elements. The random vibration problem of the impeller is solved through the Pseudo-Excitation Method considering spatial variance of the pressure field. A user-defined module is developed based on harmonic analysis to generate the auto power spectral density and variance of displacement and stress at 200 nodes. It is demonstrated that solving a random vibration problem through the Pseudo-Excitation Method is faster than the commonly adopted multiple-step transient analysis. It is concluded that evaluating the structural integrity of impeller solids in the regime of random vibration is a feasible and efficient approach at the early design stage of compressors.


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