• Journal of the Korean Society for Precision Engineering
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• v.13 no.10
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• pp.30-35
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• 1996

Tires, bushings and stabilizers are the most difficult elements in vehicle modeling for dynamic analyses. Many studies were performed for tire modeling and the primitive data of bushing elements can be obtained from the suspension designer, but there are few things for stabilizer. This paper presents simulation results for the 3 kinds of stabilizer model with the multi-body dynamic analysis program ADAMS. Each simulation result was compared with the vehicle test result, and the stabilizer model was proposed to analyze the vehicle behaviors precisely.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5D
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• pp.831-838
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• 2006

An experimental/analytic study has been conducted to understand the adverse effects of low vehicle speed, high axle load and high tire pressure on the performance of asphalt pavements. Of 33 asphalt sections at KHC test road, two sections having different base layer thickness (180 mm versus 280 mm) are adopted for rollover tests. During the test, a standard three-axle dump truck maintains a steady state condition as moving along the wheel path of a passing lane, and lateral offsets and real travel speed are measured with a laser-based wandering system. Test results suggest that vehicle speed affects both longitudinal and transverse strains at the bottom of asphalt layer (290 mm and 390 mm below the surface), and even slightly influences the measured vertical stresses at the top of subbase and subgrade due to the dynamic effect of rolling vehicle. Since the anisotropic nature of asphalt-aggregate mixtures, the difference between longitudinal and transverse strains appears prominent throughout the measurements. As the thickness of asphalt pavement increases, the measured lateral strains become larger than its corresponding longitudinal strains. Over the limited testing conditions, it is concluded that higher axle weight and higher tire pressures induce more strains and vertical stresses, leading to a premature deterioration of pavements. Finally, a layered elastic analysis overestimates the maximum strains measured under the 1st axle load, while underestimating the maximum vertical stress in both pavement sections.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.7 s.100
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• pp.788-798
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• 2005

The monopole theory has long been used to model air-pumped effect from the elastic cavities in car tire. This approach models the change of an air as a Piston moving backward and forward on a spring and equates local air movements exactly with the volume changes of the system. Thus, the monopole theory has a restricted domain of applicability due to the usual assumption of a small amplitude acoustic wave equation and acoustic monopole theory This paper describes an approach to predict the air-pumping noise of a car tyre with CFD/Kirchhoff integral method. The tyre groove is simply modeled as piston-cavity-sliding door geometry and with the aid of CFD technique flow properties in the groove of rolling car tyre are acquired.'rhese unsteady flow data are used as a air-pumping source in the next CFD calculation of full tyre-road geometry. Acoustic far field is predicted from Kirchhoff integral method by using unsteady flow data in space and time which is provided by the CFD calculation of full tyre-road domain. This approach can cover the non-linearity of acoustic monopole theory with the aid of Non-linear governing equation in CFD calculation. The method proposed in this paper is applied to the prediction of air-pumping noise of simply modeled car tyre and through the predicted results, the influence of nonlinear effect on air-pumping noise propagation is investigated.

• Elastomers and Composites
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• v.56 no.4
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• pp.243-249
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• 2021

The demand for truck bus radial (TBR) tires with enhanced fuel efficiency and wear resistance have grown in recent years. In addition, as the issue of particulate matter and air pollution increases, efforts are being made to reduce the generation of particulate matter. In this study, we investigated the effect of varying the content of butadiene rubber (BR) on the properties of the rubber compounds and the amount of particulate matter in the TBR tire tread compound. Furthermore, we utilized carbon black in the NR/BR blend compounds owing to its excellent compatibility, and we used silica in the ENR-25/BR blend compounds because it can interact chemically with epoxide groups. The NR/BR blend compounds and the ENR-25/BR blend compounds were evaluated by varying their BR content between 20 phr and 30 phr. The results showed that the ENR-25/BR blend compounds had superior wear resistance than the NR/BR blend compounds. This was caused by the interaction between silica and ENR. In addition, it was confirmed that the increased wear resistance as the BR content increased. Furthermore, compared to the NR/BR blend compounds, ENR-25/BR blend compounds exhibited a lower tan 𝛿 value at 60℃ because silica was used as filler. This indicates a higher fuel efficiency. The measurement results for wear particulate matter showed that as increasing the BR content resulted in generation of less wear particulate matter. This was caused by the increased wear resistance. Moreover, the ENR-25/BR blend compounds with excellent filler-rubber interaction exhibited lower quantities of generated wear particulate matters as compared to the NR/BR blend compounds.

• Elastomers and Composites
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• v.48 no.3
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• pp.201-208
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• 2013

In this study, effect of different amounts of sulfur and vulcanization accelerators in the acrylonitrile styrene-butadiene rubber (AN-SBR)/silica compounds on the properties of tire tread compound were studied. As a result, cure rate and degree of cross-linking of the compounds were increased due to enhanced cross-linking reactivity by the increased amounts of sulfur and vulcanization accelerators. Also, abrasion resistance and the mechanical properties such as hardness and modulus of the compounds were improved by enhanced degree of cross-linking of the compounds. For the dynamic properties, tan ${\delta}$ value at $0^{\circ}C$ was increased due to the increase of glass transition temperature ($T_g$) by enhanced degree of cross-linking of the compound, and tan ${\delta}$ value at $60^{\circ}C$ was decreased. Initial cure time ($t_1$) showed the linear relationship with tan ${\delta}$ value at $60^{\circ}C$. This result is attributed that reduced initial cure time ($t_1$) of compounds by applying increased amount of curatives can form cross-linking in early stage of vulcanization that may suppress development of filler network. This result is verified by observation on the surface of annealed compounds using AFM (atomic force microscopy). Consequently, decreased initial cure time is considered a very important parameter to reduce tan ${\delta}$ at $60^{\circ}C$ through reduced re-agglomeration of silica particles.

• Journal of Electrical Engineering and Technology
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• v.11 no.6
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• pp.1729-1734
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• 2016

The surface inspection of a steel billet is a common practice in the steel manufacturing process prior to hot rolling to produce steel wire for tire cord. This billet surface inspection is an important process because flaws on the surface may cause major failures during the product manufacturing phase. This paper presents a computer simulation based on a finite element method for a magnetic flaw detector with a function of the current intensity, the number of coil turns, and the billet proceeding speed during the production phase based on the typical condition of conventional apparatus. Based on the simulation result, the magnitude of the electromagnetic field on the surface diminished with distance from the electromagnet. In addition, the increased current intensity and the increased number of coil turns actually induced a stronger electromagnetic field on the billet surface. On the other hand, the proceeding speed of a billet in its production line had no significant effects. The result in this study may assist to reduce trial and error and to minimize the opportunity costs during the optimization process by applying the findings of this study into the operation condition in the steel billet production line.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.772-777
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• 2006

An acoustic finite element model of a bridge is developed to evaluate the noise generated by the traffic-induced vibration of the bridge. The dynamic response of a multi-girder bridge, modeled by a 3-dimensional frame element model, is analyzed with a 3-axle(8DOF) truck model and a 5-axle(l3DOF) semi-trailer. The flat plate element is used to analyze the acoustic pressure due to the fluid-structure interactions between the vibrating surface and contiguous acoustic fluid medium. The radiation fields of noise with a specified distribution of vibrating velocity and pressure on the structural surface are also computed using the Kirchhoff-Helmholtz integral. In an attempt to illustrate the influence of the structural vibration noise of a bridge to total noise level around the bridge, the random function is used to generate the vehicle noise source including the engine noise and the rolling noise interacting between the road and tire. Among the diverse parameters affecting the dynamic response of bridge, the vehicle velocity, the vehicle weight, the spatial distribution of the road surface roughness, the stiffness degradation of the bridge and the variation of the air temperature changing the air density are found to be the main factors that increase the level of vibration noise. Consequently, The amplification rate of noise increases with the traveling speed and the vehicle weight.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.04a
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• pp.185-191
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• 2002

In this study a 3-dimensional analytical model is developed, which can analyses dynamic responses of curved bridges subject to moving vehicles. A 5-axle semi-trailer is modeled to simulate the actual tire forces that are redistributed by vehicle rolling effect due to the centrifugal force. The 1-span curved bridge with two steel box girders is modeled using the frame elements. The dynamic response characteristics of curved box girder bridges are examined and compared for two different support conditions. One is the case that two shoes are arranged at the outer sides of box girders with larger space between the two shoes and the other is that two shoes at the center of each box girder. In the curved bridges, the dynamic effect of moving vehicles influences the reaction force much more than other responses, such as displacement or stress, especially the upward reaction of inner-radius shoes. It is more advantageous for the reaction considering dynamic effect when shoes are arranged further at the outer sides of box girders than when shoes at the center of each box. The shoes for curved bridges with two-box girder system should be arranged to have larger distance.

• Elastomers and Composites
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• v.55 no.3
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• pp.167-175
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• 2020

Various studies have been conducted to improve silica dispersion of silica filled tire tread compounds; among them, silica wet masterbatch (WMB) technology is known to be suitable for manufacturing silica filled compounds that have high silica content and high dispersibility. Till now, the WMB study is focused on the natural rubber (NR) or emulsion styrene-butadiene rubber (ESBR) that does not have a silica-affinity functional group, and a study of NR or ESBR having a silica-affinity functional group is still not well known. Unlike the dry masterbatch technology, the WMB technology can solve the problems associated with the high Mooney viscosity when applied to silica-friendly rubber. However, a coagulant suitable for each functional group has not yet been determined. Therefore, in this study, different coagulant applied silica WMB was prepared by applying calcium chloride, sulfuric acid, acetic acid, and propionic acid by using a carboxyl group functionalized reversible addition fragmentation chain transfer ESBR. The evaluation of the WMB compounds revealed that the calcium chloride added WMB compound showed excellent silica dispersion, abrasion resistance, and rolling resistance.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.2
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• pp.207-218
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• 2017

Improving fuel consumption, particularly that of commercial vehicles, has become a global concern. The reduction in logistics cost has been a key issue in efforts to improve fuel economy and efficiency of transportation equipment. Typical technologies for reducing reduce fuel usage include air resistance reduction technologies, tire rolling resistance technologies, and idle technologies among others. Air resistance technology is a highly effective method that can be easily applied in a short period. As with air resistance technology, several devices involving side skirt, boat tail and gap fairing have been developed based on an analytical 3-D modeling technique for reducing air resistance attributed to the vehicle configuration. The devices were on a 45 feet tractor-trailer and the emission test was done using PEMS equipment. Fuel economy was evaluated by introducing several devices to reduce outer air resistance. The test was conducted by changing the experimental method of SAE J1321 Joint TMC/SAE Fuel Consumption Test Procedure - Type II test. As a result, air resistance decreased by at least 15 % and fuel economy improved by at least 13 %. This study sought to reduce greenhouse gas and improve fuel economy by applying several devices to a test vehicle to lower air resistance.