• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.05a
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• pp.256-259
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• 2002

Recently, most vehicles has the Automatic transmission system as their transmission system. The automatic transmission system operates with fixed shift patterns. In the opposite of manual operation, it is easy and convenient for driving. Though these merit, the system can not evaluate the driver's intension because of usage of firmed shift pattern. Especially, when the load has declination the AT system must operate for engine break effect. Namely, if the vehicle drives on the load of decrease, the acceleration of the vehicle goes to high then. At that time, the shift goes to down position the vehicle has some negative acceleration with the resistance of engine. To consider driver's intension in this case, we must consider both the driving intensity of driver and the status of load. In this paper, we developed flexible automatic transmission system by using the proposed moduled neural networks which can learn the status of the load and driver's intensity As a result, we compare the transmission system using firmed shift pattern and the proposed transmission system and show the good performance in the change of shift position.

• Journal of Welding and Joining
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• v.33 no.2
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• pp.62-68
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• 2015

This study investigates the appropriate range of reverse bending load for the CTOD test of thick weld by observing improvement of pre-crack shape and determination of the limit applicable load. In order to do it, the effect of the amount of the reverse bending load on the maximum deviation of the pre-crack length was investigated by the extensive tests, and the variation of plastic zone size in way of the crack tip under reverse bending load were evaluated by FEA. With the results obtained by the experiments and FEA, the proper range of reverse bending load was suggested. The effectiveness of the reverse bending method was verified by examining the pre-crack straightness after CTOD tests of thick weld specimens with various thickness and strength.

• Structural Engineering and Mechanics
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• v.60 no.2
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• pp.237-249
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• 2016

There are constraints on truck weight, axle configurations and size imposed by departments of transportation around the globe due to structural capacity limitations of highway pavements and bridges. In spite of that, freight movers demand some vehicles that surpass the maximum size and legal weight limits to use the transportation network. Oversized trucks serve the purpose of spreading the load on the bridge; thus, reducing the load effect on the superstructure. For such vehicles, often a quick structural analysis of the existing bridges along the traveled route is needed to ensure that the structural capacity is not exceeded. For a wide vehicle having wheel gage larger than the standard 1830 mm, the girder distribution factors in the design specifications cannot be directly used to estimate the live load in the supporting girders. In this study, a simple approach that is based on finite element analysis is developed by modifying the AASHTO LRFD's girder distribution factors for slab-on-steel-girder bridges to overcome this problem. The proposed factors allow for determining the oversized vehicle bending moment and shear force effect in the individual girders as a function of the gage width characteristics. Findings of the study showed that the relationship between the girder distribution factor and gage width is more nonlinear in shear than in flexure. The proposed factors yield reasonable results compared with the finite element analysis with adequate level of conservatism.

• International Journal of Highway Engineering
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• v.11 no.2
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• pp.167-174
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• 2009

The simulation of dynamic load was conducted based on surface profile on asphalt concrete pavement, vehicle speeds, and suspension types using a truck simulation program. The results of the simulated dynamic load based on different surface profile, vehicle speeds, and suspension types are analyzed. As pavement roughness and vehicle speed are increased, the dynamic load was increased. Walking beam suspension produces greater dynamic load than air spring suspension. Pavement damage index is calculated based on covariance of dynamic load and Paris-Erdogan fracture parameter, n which is based on creep compliance tests of asphalt mixtures used in Korea. The higher covariance of dynamic load, confidence level, and fracture parameter are used, the greater pavement damage index is obtained. Specification of pavement roughness can be developed in various vehicle speeds and asphalt mixtures, and pay factor can be determined after constructing asphalt concrete pavement using pavement damage concepts.

• Journal of the Korea Safety Management & Science
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• v.18 no.4
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• pp.107-114
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• 2016

The efficiency of the purchasing and procurement logistics is important in automotive industry. The rationalization of production system is directly impact on productivity and quality. For this reason importance of logistics is high. Despite we are continuously making effort, our country are still below the level than developed country on logistics efficiency. Rising labor costs is an important factor in increasing logistics costs. So workforce reduction in logistics department is a large part. We deal with A-company inbound logistics, especially procurement logistics in automotive logistics as research object. So in this study we do research on work load balance about workers. We do research on 1,475 kinds of components in procurement process. We applied work load balance algorithm on chassis, final, sequence, trim warehouses workers. According to number of workers and average M/H, algorithm is applied in two ways. After applied work load balance algorithm we reduced numbers of workers from 28 to 20 and improved worker load balance rate from 47.1% to 93.7%.

• Journal of Korean Society of Steel Construction
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• v.25 no.4
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• pp.335-346
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• 2013

AASHTO LRFD and Korean Bridge Design Code (Limit State Design) specify to consider Truck and Lane load simultaneously determined from reliability-based live load model, and impact shall be applied to the truck load while it shall not be applied to the lane load. In this paper, vehicle-bridge interaction analysis under moving truck and lane loads were performed to estimate impact factor of the cables and girders for the selected multi-cable-stayed composite bridges with 230m, 400m and 540m main span. A 6-d.o.f. vehicle was used for truck load and a series of single-axle vehicles was applied to simulate equivalent lane load. The effect of damping ratio on the impact factor was estimated and then the essential parameters to impact factor, i.e., road surface roughness and vehicle speed were considered. The road surface roughness was randomly generated based on ISO 8608 and it was applied to the truck load only in the vehicle-bridge interaction analysis. The impact factors evaluated from dynamic interaction analysis were also compared with those by the influence line method that is currently used in design practice to estimate impact factor in cable-stayed bridge.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1994.04a
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• pp.199-208
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• 1994

One of the main objectives of the study is to propose a practical but realistic limit state model considering combined effect of axial and bending load for reliability analysis and safety assessment of cable-stayed bridge under vehicle traffic loads. This paper is intended to propose a new approach for the evaluation of reserved load carrying capacity of cable-stayed bridge under vehicle traffic loads in terms of equivalent strength, which may be defined as a bridge strength corresponding to the reliability index of the bridge. This can be derived from an inverse process based on the concept of FOSM form of reliability index. AFOSM and IST methods are used for the reliability analysis of the proposed models. The proposed reliability model and methods are applied to the safety assessment of Jindo Bridge which is one of major two cable-stayed bridges in Korea.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1103-1108
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• 2009

This paper describes the results of structural test and finite element analysis for rubber wheel-type Automatic Guideway Transit(AGT) made of aluminum honeycomb sandwich composites with WR580/NF4000 glass-fabric epoxy laminate face sheets. The static tests of vehicle structure were conducted according to JIS E7l05. These static tests have been done under vertical load, compressive load and 3-point support load. The structural integrity of AGT vehicle structure was evaluated by displacement, stress obtained from LVDT and strain gauges, and natural frequency. And finite element analysis using Ansys v11.0 was done to compare with the results of static test. The result showed that the results of structural integrity for static test were in an good agreement with these of finite element analysis.

• Advances in Computational Design
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• v.7 no.4
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• pp.371-393
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• 2022

This paper presents a three-dimensional flexible pavement simulated in ANSYS subjected to moving vehicular load on the surface of the pavement typical for the road section in Nepal. The adopted finite element (FE) model of pavement is validated with the classical theoretical formulations for half-space pavement. The validated model is further utilized to understand the damping and dynamic response of the pavement. Transient analysis of the developed FE model is done to understand the time varying response of the pavement under a moving vehicle. The material properties of pavement considered in the analysis is taken from typical road section used in Nepal. The response quantities of pavement with nonlinear viscoelastic asphalt layer are found significantly higher compared to the elastic pavement counterpart. The structural responses of the pavement decrease with increase in the vehicle speed due to less contact time between the tires of the vehicle and the road pavement.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.535-538
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• 1997

Studied in this paper was the lateral displacement of railway vehicle using the multi-body dynamic simulation program (VAMPIRE) and the BASS 501. The lateral displacement of railway vehicle is occurred by thc clearance between wheel flange and rail, the track irregularity, the property of each suspension of vehicle and the cant etc. The results of analysis shown that Vehicle is not interfere with subway platform in any conditions namely the tare and full load condition, the wheel. wear condition and the stationary and running of vehicle.