scholarly journals A virtual test bench for determining the loads in the air suspension of the rear trolley of a truck at the early stages of design

2021 ◽  
Vol 1 (3) ◽  
pp. 76-86
Author(s):  
R.O. Maksimov ◽  
◽  
I.V. Chichekin ◽  

To determine the maximum loads acting in the rear air suspension of a truck at the early stages of design there was used computer modeling based on solving equations of dynamics of solids and implemented in the Recurdyn software. The components of the developed virtual test bench, includ-ing hinges, power connections, drive axles, a wheel-hub assembly with a wheel and a support plat-form, are considered in detail. The test bench is controlled using a mathematical model created in the environment for calculating the dynamics of rigid bodies and associated with a solid suspension model by standard software tools of the application. The test bench is controlled using a mathemati-cal model created in the environment for calculating the dynamics of rigid bodies and associated with a solid suspension model by standard software tools of the application. The use of such a test bench makes it possible to determine the loads in the hinges and power connections of the suspen-sion, to determine the mutual positions of the links for each load mode, to increase the accuracy of the calculation of loads in comparison with the flat kinematic and force calculation. The mathemati-cal model of the virtual test bench allows to carry out numerous parametric studies of the suspension without the involvement of expensive full-scale prototypes. This makes it possible at the early stages of design to determine all hazardous modes, select rational parameters of the elements, and reduce design costs. The paper shows the results of modeling the operation of a virtual test bench with an air suspen-sion in the most typical loading modes, identifying the most dangerous modes. The efficiency and adequacy of the mathematical model of the suspension was proved. Examples of determining the force in all the joints of the structure, the choice of maximum loads for design calculations when designing the air suspension of vehicle were shown.

2014 ◽  
Vol 596 ◽  
pp. 17-21 ◽  
Author(s):  
Zhong Xing Li ◽  
Long Yu Ju ◽  
Hong Jiang ◽  
Xing Xu

Laterally interconnected air suspension combines the right and left air springs with pneumatic pipes, which can protect the auto-body parts from fatigue damage and increase the service life of vehicles. The mathematical model of full vehicle with laterally interconnected air suspension was established based on the analysis of its working principle, and a test bench was built. The simulation and experimental results show that, laterally interconnected air suspension can reduce the peak of dynamic body torsion load effectively, especially for steady state conditions, in which the body torsion load caused by the spring force can be nearly eliminated.


2014 ◽  
Vol 577 ◽  
pp. 273-276 ◽  
Author(s):  
Hong Jiang ◽  
Kuan Qian ◽  
Long Yu Ju ◽  
Zhen Cui

Laterally interconnected air suspension can further improve air suspension performance. This paper presents the mathematical model of full vehicle and the test bench for laterally interconnected air suspension is established. Simulation and experimental results indicate that acceleration of sprung mass is reduced by laterally interconnecting the left and right air springs, and the larger pneumatic pipe diameter is, the better damping performance of the suspension will be. Compared with the conventional air suspension, laterally interconnected air suspension brings better ride comfort and driving stability for vehicles on uneven road.


2020 ◽  
Vol 29 (54) ◽  
pp. e11604
Author(s):  
Esteban Rojas-Osorio ◽  
Andrés Julián Saavedra-Montes ◽  
Carlos Andrés Ramos-Paja

This paper evaluates the effect of the voltage harmonic distortion over the efficiency of a compact fluorescent lamp that is fed with a constant RMS voltage and constant frequency. Several works have been published about the assessment of compact fluorescent lamps, but the effect of the voltage distortion over the efficiency is still an open topic. This work focuses on designing an experiment to estimate the efficiency of a compact fluorescent lamp while changing the voltage harmonic distortion of the power supply. First, a mathematical model that represents a bus susceptible to harmonic distortion (high impedance) that feeds the compact fluorescent lamp is analyzed. Then the mathematical model is reproduced through a test bench in a laboratory of rotating electrical machines. The test bench produces a three-phase bus with constant voltage and frequency, and variable voltage harmonic distortion. The compact fluorescent lamp is subjected to varying harmonic voltage distortion while recording its electrical variables and the produced lumens to estimate its efficiency. That is a practical approach to calculate the lamp efficiency while several works limit their scope measuring only the efficiency of the input converter. The experimental results show that a variation of the voltage harmonic distortion of 8 % on a compact fluorescent lamp reduces its efficiency. Those results put into evidence the importance of regulating harmonic distortion limits to reduce or prevent the increment of power losses caused by harmonic components.


2019 ◽  
Vol 113 ◽  
pp. 01002
Author(s):  
Alessandro Vulpio ◽  
Nicola Casari ◽  
Mirko Morini ◽  
Michele Pinelli ◽  
Alessio Suman

Biomass gasification is regarded as one of the most promising technology in the renewable energy field. The outcome of such operation, i.e. the synfuel, can be exploited in several ways, for example powering engines and turbines, and is considered more flexible than the biomass itself. For this reason, a careful analysis of the gasification performance is of paramount importance for the optimization of the process. One of the techniques that can be used for such a purpose, is the numerical analysis. CFD is indeed a tool that can be of great help in the design and study of the operation of the gasifier, allowing for an accurate prediction of the operating parameters. In this work, a downdraft gasifier is considered, and the biomass is made of wood chip. The present analysis is devoted to build the numerical model and simulate all the reactions that happen inside an actual gasifier, considering the drying of the wood chip, heating, pyrolysis, and combustion. Good match with experimental results is found, making the numerical model here presented a reliable virtual test bench where investigating the effects of variation in the working parameters.


Actuators ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 117
Author(s):  
Alejandra de la Guerra ◽  
Victor M. Jimenez-Mondragon ◽  
Lizeth Torres ◽  
Rafael Escarela-Perez ◽  
Juan C. Olivares-Galvan

This article introduces an on-line fault diagnosis (FD) system to detect and recognize open-phase faults in switched reluctance motors (SRMs). Both tasks, detection and recognition, are based on functions built with the same information but from different sources. Specifically, these functions are constructed from bus current measurement provided by a sensor and from the estimate of such a current provided by an extended Kalman filter (EKF) that performs the estimation from only rotor angular position measurements. In short, the FD system only requires two measurements for employment: bus current and angular position. In order to show its efficacy, results from numerical simulations (performed in a virtual test bench) are presented. Specifically, these simulations involve the dynamics of the SRM, including the magnetic phenomena caused by the analyzed faults. The motor dynamics were obtained with finite element simulations, which guarantee results close to the actual ones.


Author(s):  
James Casey

In the literature on pseudo-rigid bodies and their applications, it is generally assumed that these bodies can undergo only a restricted class of motions, without questioning how this restriction is to be strictly enforced. In 2004, I proposed in these Proceedings that such a restriction may be regarded as a ‘global constraint’ on a deformable continuum, and influenced by ideas of Antman & Marlow from the early 1990s, I assumed that the constraint is enforced by a field of reactive stresses, and I constructed a mathematical model that idealizes pseudo-rigid bodies as globally constrained continua of finite size. In a recent article in Proceedings of the Royal Society A , the validity of this model was challenged. Essentially, the controversy revolves around the issue of working definitions versus idealized mathematical models of pseudo-rigid bodies.


Author(s):  
Daniel C. Sloope ◽  
David N. Rocheleau

A computer simulation model of the valve train of a Honda GX30 engine was modeled using Virtual Test Bed (VTB), a resistive companion dynamic simulation solver. Traditionally VTB has been exclusive to solving electrical system models but using the resistive companion equivalence of through and across variables, it can be applied to mechanical systems. This paper describes a dynamic simulation of an overhead valve engine cam-follower system using the VTB software application. The model was created to show valve train position, velocity and acceleration to aid in development of a camless engine being developed at the University of South Carolina. The mathematical model was created using governing dynamic equations. Using C++ programming, the mathematical model was transformed into a Virtual Test Bed model. The VTB model successfully shows valve train component position, velocity and acceleration. The significance of this work is its novelty in using the Virtual Test Bed environment to handle dynamic modeling of mechanical systems, whereas to date, VTB has been primarily focused on resistive companion modeling of power electronic systems. This work provides the foundation for using VTB to tackle more complex mechanical models.


Author(s):  
Ange Lu ◽  
Qiucheng Ma ◽  
Jie Ma

The lotus plumule has high medicinal value and is an important part of the lotus seed. Usually, the lotus seed must be split symmetrically into two halves through a splitting process to obtain an intact lotus plumule. However, this process is difficult to mechanize and automate, as different lotus seeds are of different sizes. In this study, a novel automatic self-adaptive splitting technology (SAST) is proposed for lotus seeds, based on a specially designed combined linkage mechanism and a roller pair centering mechanism. The technology can automatically adjust the position of the splitting point taper punch according to the size of the lotus seed and ensure that the tip of the punch is on the axis of the lotus seed. First, the centering deviation of the centering mechanism was analyzed. A mathematical model for the SAST was developed, and the key parameters were optimized using the firefly algorithm. An automatic splitting machine and a test bench were designed for centering deviation measurements, and both centering and splitting experiments were conducted. The generated maximum centering deviation of the SAST was <0.176 mm; the highest accurate splitting rates of 95% and 93.05% were achieved for unclassified and graded lotus seeds, respectively.


2019 ◽  
Vol 945 ◽  
pp. 885-892 ◽  
Author(s):  
O.E. Sysoev ◽  
A.Y. Dobryshkin ◽  
Nyein Sit Naing ◽  
A.V. Baenkhaev

The operation of a structure of thin-walled open cylindrical shells with high economic efficiency is associated with the phenomenon of oscillations and resonance from the effects of cyclic loads and systems of attached masses. The oscillation processes of such structures are not sufficiently studied at present. The article describes a test bench for testing open thin-walled cylindrical shells hinged on the edges that carry a system of attached masses, and the results of experiments on the nature of a reduced-scale shell model are presented. The attached mass system represents metal cylinders of different masses arranged in a certain sequence on the shell body. The experimental dependence of the change in the frequency spectrum of the shell oscillations on the number, mass, and location of the system of attached masses is obtained. A mathematical model is developed for the behavior of an open thin-walled cylindrical shell with a system of attached masses, consistent with the experimental data for forced vibrations of the shell.


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