• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.175-180
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• 2008

Due to the global environment problems and the consumer's need for higher vehicle performance, it becomes very important for the global car makers to reduce vehicle weight. To reduce vehicle weight, many car makers have tried to use lightweight materials, for example, aluminum, magnesium, and plastics, for the vehicle structures and components. Especially, the ASF(aluminum space frame) is known for the excellent concept of the vehicle to satisfy structural rigidity, safety performance and weight reduction. In this research, the design of experiments and the multi-disciplinary optimization technique were utilized to meet the weight and structural rigidity target of the ASF. For the structural performance of the ASF, the locations and the size of aluminum extruded frames, aluminum cast nodes, and the aluminum sheets were optimized. As a result, the optimization design procedure has been set up to meet both structural and weight target of the ASF, and the assembled ASF showed good structural performance and weight reduction.

• Journal of the Korean Society of Safety
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• v.28 no.1
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• pp.63-73
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• 2013

Dynamic strain history curve measured in the field is influenced by various factors such as vehicle type, speed, noise, temperature and running location etc.. Because such curve is used for vehicle weight estimation methodology suggested by Moses, exact strain history curve is the most important thing for exact estimation of vehicle weight. In this paper, effect of such factors mentioned above is investigated on the measured strain history curves, and results of weight estimation of vehicles are discussed quantitatively. From this study, it was known that temperature effect contained in the strain history curve measured for long time in-site gives the biggest effect on result of weight estimation and it can be removed by using the mode value. Furthermore, gross vehicle weight can be estimated within 5% error corresponding to A class of the European classification if effects of temperature and noise are removed and vehicle properties such as speed, axle arrangement and running location are considered properly.

• Journal of the Korean Graphic Arts Communication Society
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• v.23 no.2
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• pp.1-14
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• 2005

Generally, printing inks are composed of pigment, vehicle and additive. Among others, the vehicle transfers the pigment to substrate and then binds it on the surface. So, rheological properties of the vehicle are an important factor which has influence on printability. Thus, in this study, rheology of the vehicle was investigated by using rotational rheometer according to molecular weight of resin. Also, emlusion rheology of water in oil type and its microstructure were examined with increasing the shear rate. Consequently, the following results were obtained: (1) By viscometric flow test, zero shear viscosity and shear thinning index of vehicle increased with increasing the molecular weight of resin. (2) By relaxation and creep test, relaxation time and retardation time of vehicle increased with increasing the molecular weight of resin. (3) By frequency sweep test, crossover point of vehicle increased with increasing the molecular weight of resin. (4) G' and G" of emlusions increased with increasing the molecular weight by amplitude sweep test. (5) The shape of water drop in emlusions was changed to the capillary tube.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.2
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• pp.102-107
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• 2019

The vehicle market has developed environment-friendly vehicles to comply with fuel economy regulations and exhaust regulations that have become stricter and stricter over time. Many studies have been conducted to improve the travel performance and fuel economy of environment-friendly vehicles, and vehicle manufacturers have been studying how to manufacture light-weight vehicles in order to improve the fuel economy of both existing vehicles and the newer environment-friendly vehicles. Exemplary light-weight vehicle technologies optimizes the design of the vehicle body structure, which is a vehicle weight-reducing method that modifies component shapes or layouts to optimize the structure of the vehicle. In addition, the new process technology uses new light-weight and very strong materials, and not typical materials, to manufacture light-weight vehicles. This study aims at the optimal design of vehicle body structures using multi-materials for the Fender-Apron, which is an important frame member for the external front side of a vehicle body, by conducting FEA (Finite Element Analysis) and multi-material bonding.

• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.4
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• pp.211-218
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• 2000

Many bridges are severely damaged by the overloaded heavy vehicle and the trend will become more serious because the traffic volume is continuously increasing. Currently, the vehicles with gross weights over 40 tonf or axle weight over 10 tonf are not allowed on the public road. However, this regulation is not based on a systematic study on the bridge capacity and assumed to be much too conservative depending on the vehicle types and bridge types. In this study, the permit weights of heavy vehicles of diverse axle spacings and axle load distribution are calculated considering the structural characteristics of bridge superstructures. In order to consider the various load effects of heavy weight vehicle crossings, three conditions are considered in the calculation of permit vehicle load. From the results, the permit vehicle weights of the simple girder bridges are calculated.

• Proceedings of the KSME Conference
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• 2000.11a
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• pp.363-369
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• 2000

Due to environmental problem for reduction in fuel consumption, vehicle emission and etc., many automotive makers are trying to reduce the weight of the vehicle. The most effective way to reduce the weight of vehicle is to use lighter materials, aluminum, plastics. Aluminum Space Frame has many advantages in weight reduction, body stiffness, ease of model change and so on. So, most of automotive manufacturers are attempting to develope Aluminum Space Frame body. For these reasons, we have developed Aluminum Intensive Vehicle based on steel monocoque body with Hyundai Motor Company. We achieved about 30% weight reduction, the stiffness of our model was higher than that of conventional steel monocoque body. In this paper, with optimization using FEM analysis, we could get more weight reduction and body stiffness increase. In the long run, we analyzed by means of simulation using PAM-CRASH to evaluate crush and crash characteristic of Aluminum Intensive Vehicle in comparison to steel monocoque automotive.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.6
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• pp.130-135
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• 2018

Currently the automobile market is developing eco-friendly vehicles in order to cope with fuel efficiency regulations. Many studies have been conducted to improve travel performance and fuel economy of the environment-friendly vehicles, and vehicle manufacturers study how to manufacture light-weight vehicles for improving fuel economy for both existing vehicles and environment-friendly vehicles. Exemplary light-weight vehicle technologies include optimal design of vehicle body structure which is a light-weight vehicle method by changing component shapes or layout to optimize the vehicle body structure and the new process technology for using new light-weight and very strong materials Various studies.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.5
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• pp.95-107
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• 2016

The axle weight of a vehicle in motion can be measured with a low-speed or high-speed weigh-in-motion (WIM). However, the axial load dynamically change depending on the vehicle's characteristics-such as the chassis or axle structure-or the characteristics of the driving environment such as road flatness. The changes in dynamic load lead to differences between the vehicle's weight measured at rest and the vehicle's weight measured in motion. For this Study, an experiment was conducted with an instrumented vehicle to analyze the range of errors caused by uncontrollable environmental factors by identifying the characteristics of the dynamic load changes of a vehicle in motion, and determine the appropriate scale for the accuracy evaluation of a high-speed WIM, as a preparatory research for the introduction of unmanned overweight enforcement systems in the future. The key findings from the experiment are summarized as follows. First, The gross weight of the tested vehicle changed by approximately 1% at low velocities and approximately by 4% at high velocities, and the vehicle's axle weight changed by approximately 1-3%, at low velocities and by 2-9% at high velocities. A single axle showed larger weight changes than individual axles in a group. Secondly, The vehicle's gross weight and the axle weight on the impact section were up to eight times and three-to-twelve times higher, respectively, than its gross weight and the axle weight on the flat section. The vibration frequency of the vehicle's dynamic load was measured at between 2.4 and 5.8Hz, and found to return to the normal amplitude after moving approximately 30 meters.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.1
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• pp.216-233
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• 2002

Due to the environmental problems of fuel consumption and vehicle emission, etc., automotive makers are trying to reduce the weight of vehicles. The most effective way to reduce a vehicle weight is to use lighter materials, such as aluminum and plastics. Aluminum Intensive Vehicle(AIV) has many advantages in the aspects of weight reduction, body stiffness and model change. So, most of automotive manufacturers are attempting to develop AIV using Aluminum Space Frame(ASF). The weight of AIV can be generally reduced to about 30% than that of conventional steel vehicle without the loss of impact energy absorbing capability. And the body stiffness of AIV is higher than that of conventional steel monocoque body. In this study, Aluminum Intensive Vehicle is developed and analyzed on the basis of steel monocoque body. The energy absorbing characteristics of aluminum extrusion components are investigated from the test and simulation results. The crush and crash characteristics of AIV based on the FMVSS 208 regulations are evaluated in comparison with steel monocoque. Using these results, the design concepts of the effective energy absorbing members and the design guide line to improve crashworthiness for AIV are suggested.

• Journal of the korean Society of Automotive Engineers
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• v.12 no.5
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• pp.97-106
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• 1990

A method of weight evaluation of the load-bearing structural elements of cars is presented and the weight ratio of the analysis model is investigated. Replacing the materials of floor elements of the car into the high-strength steel, a considerable weight-reduction of the model has been obtained. The 1500cc model is selected for the present study and the stick model analysis is employed for the structural analysis. The torsional stiffness of the weight-reduced model is also evaluated and it is shown it has a reasonable rigidity. The ratio of the weight of the load-bearing structural elements to the unladen vehicle weight of cars is about 0.12for the 1500cc model and the weight-reduction of this study can be obtained around 17% of the weight of the load-bearing structural elements.