Cargo Ride Safety Analysis of Trucks for Four Excitation Cases

2010 ◽  
Vol 118-120 ◽  
pp. 660-664
Author(s):  
Li Qun Guo ◽  
Deng Feng Wang

Excessive levels of vibration in commercial vehicles, due to excitation from the road irregularities, can lead to cargo damage and safety problems. In order to study the cargo ride safety problem, a three dimension (3D) finite element model of full vehicle was established, which differs from the previous two dimension (2D) one. The computation algorithm for acceleration power spectral density (PSD) and root mean square (RMS) was also given. For the sake of comparisons, two frames with different stiffness were given in the computations of PSD and RMS of body vertical accelerations for four excitation cases. The computed results showed that when the stiffness of the frame increases, the RMS values of the body decreases strongly at the frequency band 14-26Hz, which can effectively improve the cargo ride safety.

2014 ◽  
Vol 968 ◽  
pp. 259-262
Author(s):  
Li Qiang Jin ◽  
Yue Liu ◽  
Jian Hua Li ◽  
Gang He

In this paper, a new control theory will be proposed for the purpose of enhancing vehicle ride performance. In the first step, a quarter car model with two DOF will be analyzed after which the classical semi-active control idea and a new control method will be built. Then a new hybrid control model based on body acceleration and classical one will be provided, after which the advantage of this controller will be studied. All the models that proposed will be accomplished through matlab/simulink. The outcome parameters of two types, namely, the body acceleration and the suspension deflection will be compared in frequency domain among three conditions which can be described as passive, classical semi-active control and hybrid control respectively. Then random excitation will be given as the road input to get power spectral density curves for further compare. Though the curves we can easily come into a conclusion that vehicle suspensions armed with this new controller will show the best ride properties which hold practical values.


2014 ◽  
Vol 530-531 ◽  
pp. 251-255
Author(s):  
Jian Rong Yang ◽  
Yu Bai ◽  
Xiao Dong Yang ◽  
Wei Ming Zhu

Three dimension finite element analysis and full-scale testing are carried out on a newly-built self-anchored suspension bridge. The 3D finite element model of the bridge is generated using a commercially available finite element package. The bridge is modeled under service loads, and the model results are compared to the results of field testing of the structure. Detailed experimental procedure is presented including the data acquisition system, testing truck, and the load distribution. Measured and calculated displacements are in reasonable concordance. And residual deformations meet the specification of the codes, no cracking opening.


2011 ◽  
Vol 308-310 ◽  
pp. 2374-2378
Author(s):  
Shu Hua Pan ◽  
Yu Dong Chen

Most of the component optimizations of trucks are limited to the individual component because of the complex coupling relations between components. Focusing on such difficult optimal problem, the conception of static modal stiffness was introduced and static modal stiffness sensitivity was defined. The method for computing static modal stiffness sensitivities was also developed. The proposed method was applied to the static modal stiffness sensitivities analysis of the frame of the truck under full vehicle environment. In the computations, a three dimension finite element model for full vehicle was established and the frame was divided into 13 superelements. The static modal stiffness sensitivities obtained can be used to improve the frame design.


2015 ◽  
Vol 23 (03) ◽  
pp. 1550009 ◽  
Author(s):  
C. Prieto Gajardo ◽  
L. Godinho ◽  
P. Amado-Mendes ◽  
J. M. Barrigon Morillas

Acoustic barriers are a well-known environmental noise mitigation solution, which is widely used nowadays. In this work, it is expected to contribute to the body of knowledge regarding the physical and technical behavior of those barriers by developing and implementing a set of models that allow an accurate analysis of noise barriers with new configuration types. A 2.5D boundary-only numerical model is developed and implemented, and computational analyses are performed in order to compare different surface profiles of the acoustic barriers. The particular case in which two acoustic barriers are used, one at each side of the road, is addressed.


2022 ◽  
Vol 19 (4) ◽  
pp. 34-39
Author(s):  
I. O. Chernyaev ◽  
S. A. Evtyukov

 Developments in adaptive systems for maintenance and repair of automotive vehicles set the task of monitoring the conditions of their operation. One of the main factors determining these conditions is the type of road surface.The article describes the results of identification of the type (and condition) of the road surface obtained by theoretical and experimental methods based on the analysis of vertical accelerations recorded on the vehicle body.The purpose of research was to provide a possibility of continuous monitoring of the type of road surface on which a vehicle is driving, with the subsequent application of the obtained data to correct maintenance intervals. The results of experiments have shown the dependence of the vertical acceleration of the body on the micro-profile of the road surface. The described experimentally obtained profiles of vertical accelerations refer to different types of road surface in different conditions. For quantitative assessment, it is proposed to calculate the average level of accelerations as an integral average over a certain time interval.The results of the experiments have allowed to substantiate the empirical dependence of the average level of accelerations on speed of a vehicle. Based on this dependence, a method is proposed for recalculating the current values of the average levels of accelerations obtained at different speeds into values adjusted to the base speed to ensure the possibility of their comparison.It is shown that based on the values of average acceleration levels obtained through operation monitoring regarding a previously known type of road surface, it is possible to determine its condition. A short algorithm is formulated for practical implementation and assessment of road conditions of traffic flows. As for hardware, it is proposed not to equip a vehicle with additional sensors but to use operational standard accelerometers as part of in-vehicle emergency call systems, e.g., ERA-GLONASS equipment units. 


2019 ◽  
Vol 13 (2) ◽  
pp. 181-188
Author(s):  
Meng Liu ◽  
Guohe Li ◽  
Xueli Zhao ◽  
Xiaole Qi ◽  
Shanshan Zhao

Background: Finite element simulation has become an important method for the mechanism research of metal machining in recent years. Objective: To study the cutting mechanism of hardened 45 steel (45HRC), and improve the processing efficiency and quality. Methods: A 3D oblique finite element model of traditional turning of hardened 45 steel based on ABAQUS was established in this paper. The feasibility of the finite element model was verified by experiment, and the influence of cutting parameters on cutting force was predicted by single factor experiment and orthogonal experiment based on simulation. Finally, the empirical formula of cutting force was fitted by MATLAB. Besides, a lot of patents on 3D finite element simulation for metal machining were studied. Results: The results show that the 3D oblique finite element model can predict three direction cutting force, the 3D chip shape, and other variables of metal machining and the prediction errors of three direction cutting force are 5%, 9.02%, and 8.56%. The results of single factor experiment and orthogonal experiment are in good agreement with similar research, which shows that the model can meet the needs for engineering application. Besides, the empirical formula and the prediction results of cutting force are helpful for the parameters optimization and tool design. Conclusion: A 3D oblique finite element model of traditional turning of hardened 45 steel is established, based on ABAQUS, and the validation is carried out by comparing with experiment.


Author(s):  
Tom Partridge ◽  
Lorelei Gherman ◽  
David Morris ◽  
Roger Light ◽  
Andrew Leslie ◽  
...  

Transferring sick premature infants between hospitals increases the risk of severe brain injury, potentially linked to the excessive exposure to noise, vibration and driving-related accelerations. One method of reducing these levels may be to travel along smoother and quieter roads at an optimal speed, however this requires mass data on the effect of roads on the environment within ambulances. An app for the Android operating system has been developed for the purpose of recording vibration, noise levels, location and speed data during ambulance journeys. Smartphone accelerometers were calibrated using sinusoidal excitation and the microphones using calibrated pink noise. Four smartphones were provided to the local neonatal transport team and mounted on their neonatal transport systems to collect data. Repeatability of app recordings was assessed by comparing 37 journeys, made during the study period, along an 8.5 km single carriageway. The smartphones were found to have an accelerometer accurate to 5% up to 55 Hz and microphone accurate to 0.8 dB up to 80 dB. Use of the app was readily adopted by the neonatal transport team, recording more than 97,000 km of journeys in 1 year. To enable comparison between journeys, the 8.5 km route was split into 10 m segments. Interquartile ranges for vehicle speed, vertical acceleration and maximum noise level were consistent across all segments (within 0.99 m . s−1, 0.13 m · s−2 and 1.4 dB, respectively). Vertical accelerations registered were representative of the road surface. Noise levels correlated with vehicle speed. Android smartphones are a viable method of accurate mass data collection for this application. We now propose to utilise this approach to reduce potential harmful exposure, from vibration and noise, by routing ambulances along the most comfortable roads.


2021 ◽  
Vol 62 ◽  
pp. 302-312
Author(s):  
Ninggang Shen ◽  
Avik Samanta ◽  
Wayne W. Cai ◽  
Teresa Rinker ◽  
Blair Carlson ◽  
...  

Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1644
Author(s):  
Qian Zhang ◽  
Huijuan Liu ◽  
Tengfei Song ◽  
Zhenyang Zhang

A novel, improved equivalent circuit model of double-sided linear induction motors (DLIMs) is proposed, which takes the skin effect and the nonzero leakage reactance of the secondary, longitudinal, and transverse end effects into consideration. Firstly, the traditional equivalent circuit with longitudinal and transverse end effects are briefly reviewed. Additionally, the correction coefficients for longitudinal and transverse end effects derived by one-dimensional analysis models are given. Secondly, correction factors for skin effect, which reflects the inhomogeneous air gap magnetic field vertically, and the secondary leakage reactance are derived by the quasi-two-dimensional analysis model. Then, the proposed equivalent circuit is presented, and the excitation reactance and secondary resistance are modified by the correction coefficients derived from the three analytical models. Finally, a three-dimensional (3D) finite element model is used to verify the proposed equivalent circuit model under varying air gap width and frequency, and the results are also compared with that of the traditional equivalent circuit models. The calculated thrust characteristics by the proposed equivalent circuit and 3D finite element model are experimentally validated under a constant voltage–frequency drive.


Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3849
Author(s):  
Martin Svoboda ◽  
Milan Chalupa ◽  
Karel Jelen ◽  
František Lopot ◽  
Petr Kubový ◽  
...  

The article deals with the measurement of dynamic effects that are transmitted to the driver (passenger) when driving in a car over obstacles. The measurements were performed in a real environment on a defined track at different driving speeds and different distributions of obstacles on the road. The reaction of the human organism, respectively the load of the cervical vertebrae and the heads of the driver and passenger, was measured. Experimental measurements were performed for different variants of driving conditions on a 28-year-old and healthy man. The measurement’s main objective was to determine the acceleration values of the seats in the vehicle in the vertical movement of parts of the vehicle cabin and to determine the dynamic effects that are transmitted to the driver and passenger in a car when driving over obstacles. The measurements were performed in a real environment on a defined track at various driving speeds and diverse distributions of obstacles on the road. The acceleration values on the vehicle’s axles and the structure of the driver’s and front passenger’s seats, under the buttocks, at the top of the head (Vertex Parietal Bone) and the C7 cervical vertebra (Vertebra Cervicales), were measured. The result of the experiment was to determine the maximum magnitudes of acceleration in the vertical direction on the body of the driver and the passenger of the vehicle when passing a passenger vehicle over obstacles. The analysis of the experiment’s results is the basis for determining the future direction of the research.


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