scholarly journals Analysis and characterization of the friction of vehicle body vibration dampers

2020 ◽  
Vol 5 (3-4) ◽  
pp. 79-90
Author(s):  
Fridtjof Körner ◽  
Ralph Mayer
Keyword(s):  
Aluminum Matrix ◽  
Simulation Models ◽  
Vehicle Body ◽  
Aluminum Matrix Composites ◽  
Damping Force ◽  
Friction Behavior ◽  
Movement Velocity ◽  
Body Vibration ◽  
The Road ◽  
Contact Surfaces

Abstract The friction at the contact surfaces of a vehicle body vibration damper, which are moved relatively to each other, influences its transmission behavior at the start of movement (breakaway force) as well as with excitation signals of higher velocity and thus has an impact on the comfort properties of the damper. According to Vibracoustic (Die wichtigsten Kriterien für deutsche Autofahrer beim Autokauf, Springer Fachmedien Wiesbaden GmbH, Wiesbaden, 2019), for most German drivers (63%) comfort (in addition to brand and appearance) before driving dynamics (53%) and environmental compatibility (48%) is the most important criteria when evaluating a new car, which explains the importance of this vehicle characteristics. Furthermore, the friction is present with any relative movement of the damper and is, therefore, relevant for the design of the damper and the associated vertical dynamics. The friction is generally determined in the fully assembled state of the damper, including oil filling and gas pressure at a very low movement velocity to eliminate the influence of the damping force. This measurement method allows no or only inadequate statements about the friction behavior at, e.g. more dynamic excitation scenarios. As a result, the aim should be to characterize the friction properties without the influence of hydraulic damping at the start of movement or reversal of movement, as well as at higher movement velocities. Another goal is to evaluate the influence of the internal pressure of the damper on its friction behavior. The test damper used here is a commercially available monotube damper that has been modified in accordance with the requirements for these tests. The results shown below can be used as starting variables for further investigations for the targeted optimization of the friction properties and thus for the improvement of driving comfort. The reduction in damper friction promises an increase in comfort due to the improved decoupling of the vehicle body from the road excitation. Furthermore, the data obtained enable the level of detail of simulation models to be increased and serve as a basis for comparing different friction pairings and contact surfaces in the damper. For the substitution of coatings (chrome-free piston rods → environmental protection) or tube materials (aluminum matrix composites → lightweight construction) as well as for changes in the surface structure and roughness, the results enable an evaluation of the friction properties compared to conventional dampers and the adjustment of the friction pairings in the sense of the best possible functionality.

Wear Resistance of Graphite / Aluminium Composites that Prepared by Stirring Casting

2013 ◽  
Vol 683 ◽  
pp. 333-338 ◽  
Author(s):  
Lin Li Wu ◽  
Wen Jing Yang ◽  
Jian Rong Xu ◽  
Guang Chun Yao
Keyword(s):  
Friction Factor ◽  
Dry Friction ◽  
Relative Rate ◽  
Aluminum Matrix ◽  
Stir Casting ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Bulk Alloy ◽  
Friction Behavior ◽  
Graphite Particles

The graphite reinforced aluminum matrix composites were prepared by using stir-casting in this paper, with bulk alloy of ZL111, reinforcement of graphite particles coated with oxide, and the friction behavior was investigated perfectly. The results indicated that, the aluminum matrix composites reinforced with 6 wt.% graphite particles coated with oxide have a good property of self-lubrication under the condition of dry friction with a pressure of 40 N, a relative rate of 2.62 m/s of frictional backing gear, a wear time of 60 min, in addition, the friction factor and the wear capacity of the graphite / aluminum matrix composites were less than those of bulk alloy. Moreover, the friction factor and the wear capacity of the graphite / aluminum matrix composites decreased with an increase in mass fraction of the graphite coated with oxide, and the friction factor of composites became bigger while the fraction of the graphite particles was over 6wt.%.

Non-Contact Vehicle Overload Identification Method Based on Body Vibration Theory

2019 ◽  
Author(s):  
Yiran Ding ◽  
Daolin Zhou ◽  
Shimin Yu ◽  
Zhenyu Wang ◽  
Gangfeng Tan
Keyword(s):  
Vibrational Excitation ◽  
Vibration Response ◽  
Intelligent Vehicles ◽  
The Body ◽  
Vehicle Body ◽  
Response Model ◽  
Characteristic Parameters ◽  
Body Vibration ◽  
The Road ◽  
Traffic Efficiency

Abstract Vehicle overload seriously affects the traffic safety, damages the road infrastructure, and the road service life is reduced. There are many shortcomings in the current detection methods for overloaded vehicles. Traditional static weighing stations are relatively fixed and affect the road traffic efficiency; the cost of weighing in motion station is high, while the precision is not enough; on-board weighing electronic products require the modification of vehicles, which is difficult to promote. In this paper, a non-contact overload detection method based on body vibration is proposed. After the analyzation of the body vibration response of dynamic vehicles under specific vibrational excitation, the load value data can be obtained combined with standard parameters and mathematical calculation model. Firstly, the body vibration response model under specific excitation is established. Then, roadbed facilities are arranged according to specific requirements, cameras calibration are finished, and the identification environment is built. Machine vision technology is used to identify the vibration track of the characteristic point on the vehicle body in the vertical direction. The vibration response characteristic parameters are extracted using the established response model. Finally, the vehicle load value data can be obtained by resolve the characteristic parameters. Compared with the rated load data in the database, the overload judgment of the vehicle is obtained. In the experiment part, the road speed-control hump was used as the vibration excitation source. The vehicle experiments were carried out with Dongfeng Aeolus S30 and Yuejin Shangjun X500. The results show that the load identification error can be controlled within 20%–30%. This method above can detect overload vehicles without affecting the traffic efficiency and also has certain guiding significance for the development of intelligent vehicles.

Effect of temperature on wear and friction behavior of as-cast and heat-treated LM25/SiC aluminum matrix composites

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Vishal R. Mehta ◽  
Mayur P. Sutaria
Keyword(s):  
Aluminum Matrix ◽  
Effect Of Temperature ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Friction Behavior ◽  
Sliding Speed ◽  
Content Type ◽  
Heat Treated ◽  
Temperature Load ◽  
Wear And Friction

Purpose The purpose of this paper is to evaluate the influence of temperature, load and sliding speed on wear and friction behavior of LM25/SiC composites in as-cast and heat-treated conditions. Design/methodology/approach The LM25/SiC aluminum matrix composites (AMCs) were prepared using the stir casting process. The wear tests were carried out using a pin-on-disc setup in dry condition. The three levels of each parameter, i.e. 100, 150 and 200°C operating temperature; 15, 25 and 35 N load; 0.8, 1.6 and 2.4 m/sec sliding speed, were considered for the investigation. ANOVA has been carried out to evaluate the percentage contribution of parameters. Scanning electron microscope analysis of worn surfaces has been carried out to understand the wear mechanism. Findings The wear and coefficient of friction (COF) increase with the increase in the temperature, load and sliding speed within a selected range for as-cast as well as heat-treated LM25/SiC AMCs. The mean values of wear and COF in heat-treated samples were found to be lower than as-cast samples for all cases. It was observed that the percentage wear increases significantly as temperature increases in as-cast AMCS. Mild to severe wear transition was observed at 150°C. In heat-treated AMCs, mild wear was observed irrespective of temperature. It was also observed that as the temperature increases, transition of wear mechanism from abrasive to adhesive (including delamination) occurs earlier in as-cast samples as compared to heat-treated samples. Originality/value There is a lack of data on combined effect of temperature, load and sliding speed on tribological aspects of as-cast and heat-treated LM25/SiC AMCs, limiting its applications. The present research work has addressed this gap.

HIGH TEMPERATURE TRIBOLOGICAL BEHAVIOR OF STIR-CAST Al–TiB2 METAL MATRIX COMPOSITES

2018 ◽  
Vol 25 (08) ◽  
pp. 1850122 ◽  
Author(s):  
SUSWAGATA PORIA ◽  
GOUTAM SUTRADHAR ◽  
PRASANTA SAHOO
Keyword(s):  
High Temperature ◽  
Tribological Behavior ◽  
Operating Temperature ◽  
Normal Load ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Friction Behavior ◽  
Sem Images ◽  
X Ray

This study considers high temperature tribological behavior of Al-TiB2 aluminum matrix composites (AMCs) fabricated through stir cast method. Effect of operating temperature on wear and friction behavior is studied for four different weight percentages of reinforcements using a high-temperature tribo-tester over a temperature range of 50[Formula: see text]C–250[Formula: see text]C under normal load in the range of 25–75[Formula: see text]N. Surface morphology and wear debris are studied through scanning electron microscopy (SEM) images. Energy dispersive X-ray (EDAX) and X-ray diffraction (XRD) studies are performed to observe the wear mechanism at high temperature. Increase in the amount of reinforcement improves wear resistance of composites at all temperatures. Friction and rate of wear are found to increase with operating temperature. Formation of oxide layers and softening of the surface are found to play crucial role in controlling the tribological behavior of stir cast Al–TiB2 composites at high operating temperatures.

Using explosive energy for processing aluminum matrix composites

2000 ◽  
Vol 10 (PR9) ◽  
pp. Pr9-119-Pr9-122
Author(s):  
V. Popov ◽  
V. Gulbin ◽  
E. Sungurov
Keyword(s):  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Explosive Energy

Effect of Titanium Carbide Particles on Mechanical Properties of Aluminum Matrix Composites

2017 ◽  
Vol 5 (2) ◽  
pp. 20-30
Author(s):  
Zaman Khalil Ibrahim
Keyword(s):  
Mechanical Properties ◽  
Titanium Carbide ◽  
Compression Strength ◽  
Volume Fraction ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Powder Metallurgy Technique ◽  
Carbide Particles ◽  
Properties Of Composites

In this research aluminum matrix composites (AMCs) was reinforced by titanium carbide (TiC) particles and was produced. Powder metallurgy technique (PM) has been used to fabricate AMCs reinforced with various amounts (0%, 4%, 8%, 12%, 16% and 20% volume fraction) of TiC particles to study the effect of different volume fractions on mechanical properties of the Al-TiC composites. Measurements of compression strength and hardness showed that mechanical properties of composites increased with an increase in volume fraction of TiC Particles. Al-20 % vol. TiC composites exhibited the best properties with hardness value (97HRB) and compression strength value (275Mpa).

The prediction of vehicle vibration transmitted to the occupant using a modular transfer matrix

2021 ◽  
pp. 107754632199759
Author(s):  
Jianchun Yao ◽  
Mohammad Fard ◽  
John L Davy ◽  
Kazuhito Kato
Keyword(s):  
Finite Element ◽  
Transfer Matrix ◽  
Dynamic Performance ◽  
Complex Structure ◽  
Vehicle Body ◽  
Computational Time ◽  
Accurate Estimation ◽  
Finite Element Models ◽  
Transfer Matrices ◽  
Body Vibration

Industry is moving towards more data-oriented design and analyses to solve complex analytical problems. Solving complex and large finite element models is still challenging and requires high computational time and resources. Here, a modular method is presented to predict the transmission of vehicle body vibration to the occupants’ body by combining the numerical transfer matrices of the subsystems. The transfer matrices of the subsystems are presented in the form of data which is sourced from either physical tests or finite element models. The structural dynamics of the vehicle body is represented using a transfer matrix at each of the seat mounting points in three triaxial (X–Y–Z) orientations. The proposed method provides an accurate estimation of the transmission of the vehicle body vibration to the seat frame and the seated occupant. This method allows the combination of conventional finite element analytical model data and the experimental data of subsystems to accurately predict the dynamic performance of the complex structure. The numerical transfer matrices can also be the subject of machine learning for various applications such as for the prediction of the vibration discomfort of the occupant with different seat and foam designs and with different physical characteristics of the occupant body.

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