• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.30 no.4
• /
• pp.297-306
• /
• 2017

The concrete median barrier used currently in South Korea was developed the impact level of SB5-B(270kJ). However, the impact level of SB6(420kJ) should be considered in many placed with the increased accident of heavy vehicles. In order to increase the impact resistance of newly developed concrete median barrier, the computer simulation was conducted before real field test. For the accurate behavior of concrete, the parameter, such as impact vehicle, concrete cover depth and deterioration, was important. In this paper, a parametric study was conducted depending on vehicle curb weight, concrete cover depth and level of deterioration. The impact resistance of concrete median barrier was severely changed depending on vehicle curb weight and concrete cover depth. Furthermore, the impact resistance of concrete median barrier was also decreased due to deterioration of concrete, therefore the repair and rehabilitation should be conducted for damaged concrete depending on deterioration level. Therefore, vehicle curb weight, cover depth of concrete structures and deterioration level of concrete should be carefully considered for conducting analysis of concrete structure to vehicle collision.

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

• Transactions of the Korean hydrogen and new energy society
• /
• v.29 no.5
• /
• pp.497-502
• /
• 2018

In Korea, passenger car and van using LPG fuel including taxi constantly increased due to the high cost of fuel. Recently, the emission standard has continuously tightened in the world. In this investigation was conducted the greenhouse gas emission characteristics of LPG vehicles according to the displacement and weight. Exhaust emission characteristics of 13 test LPG vehicles from about 1.0 L to 3.0 L displacements were measured and analyzed by using chassis dynamometer and emission analyzer. It is revealed that the greenhouse gas emission was showed the increasing tendency as the displacement and curb weight increased. Also, greenhouse gas emission of SC03 driving cycle has highest value and that of HWFET driving cycle shows the lowest value.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.10
• /
• pp.1323-1328
• /
• 2011

In the current design process for the lower arm used in automobile parts, an optimal solution of its various design variables should be found through exploration of the design space approximated using the response surface model formulated with a first- or second-order polynomial equation. In this study, a multi-level computational DOE (design of experiment) was carried out to explore the design space showing nonlinear behavior, in terms of factors such as the total weight and applied stress of the lower arm, where a fractional-factorial orthogonal array based on the artificial neural network model was introduced. In addition, the tolerance robustness of the optimal solution was estimated using a tolerance optimization with six sigma constraints, taking into account the tolerances occurring in the design variables.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.14 no.6
• /
• pp.190-194
• /
• 2006

This research investigates vehicle structure acceleration and vehicle deformation with RCAR crash test. To investigate vehicle damage characteristics in an individual case, it is possible to RCAR low speed crash test. In this study, two tests were conducted to evaluate difference between RCAR new condition and RCAR old condition. A two large vehicles were subjected to a frontal crash test at a speed of 15km/h with an offset of 40% $10^{\circ}$ angle barrier and flat barrier. The results of the 15km/h with an offset of 40% $10^{\circ}$ angle barrier revealed high acceleration value on the vehicle structure and high repair cost compared to the RCAR 15km/h with an offset of 40% flat barrier. So in order to improve damage characteristics in low speed crash of vehicle structure and body component of the monocoque type passenger vehicles, the end of front side member and front back beam should be designed with optimum level and to supply the end of front side member as a partial condition approx 300mm.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.13 no.2
• /
• pp.108-113
• /
• 2005

The damageability and repairability of similar platform type vehicles could be very concerned with design optimization. In all the vehicles crash tested, small size passenger vehicles were weakness in aspect of damageability and repairability. The most critical area appears to be repair cost considering that parts cost is the largest portion of total repair cost segments. Besides repair cost, attaching method of front sidemember and subframe are placed special importance for impact energy absorption and damageability and repairability. So in order to improve damageability and repairability of vehicle structure and body component of the monocoque type passenger vehicles, the end of front side member and front back beam should be designed with optimum level and to supply the end of front side member as a partial condition approx 300mm. The effectiveness of design concept on the 40% offset frontal impact characteristics of the passenger vehicle structure is investigated and summarized.

• Journal of ILASS-Korea
• /
• v.25 no.1
• /
• pp.34-39
• /
• 2020

Automotive manufacturers are applying technologies for greenhouse gas reduction such as vehicle weight reduction, engine downsizing, direct injection technology, variable valves and transmission performance improvement to achieve the targets for enhanced greenhouse gas and fuel consumption efficiency. In this paper, compared and analyzed greenhouse emissions according to engine capacity, engine displacement, curb weight and sales volume of hybrid and internal combustion engine passenger vehicles. Hybrid emit 32~39% less greenhouse gas than internal combustion engines through the combined mode test method. Hybrid electric vehicle's curb weight was about 7% heavier on average for the same engine displacement, while greenhouse gas was about 36% lower. It was confirmed that in order to reduce the emission of pollutants of greenhouse gases as well as the air pollutants, it is necessary to expand the supply of eco-friendly vehicles.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.9
• /
• pp.133-140
• /
• 2016

The Ministry of Land, Infrastructure and Transport has introduced low-floor buses, which are convenient for passengers getting on and off the bus and for the handicapped. The standard bus model is 11 m long and uses compressed natural gas (CNG). However, this model has drawbacks in narrow rural road conditions such as those in farming and fishing villages and mountainous areas, as well as difficulty in refueling since CNG facilities are not readily available. In this study, running resistance values were obtained by coasting performance tests on actual roads using a Tata Daewoo LF-40 model with three different weight conditions: curb vehicle weight (CVW), half vehicle weight (HVW), and gross vehicle weight (GVW).The test methods include WHVC, NIER-06, and constant-speed driving at 60 km/h. These tests were used to measure the fuel economy of vehicles other than the target vehicles to obtain the combined fuel economy. The energy efficiency was highest in the case of CVW. In the WHVC mode, the fuel consumption rates of HVW and GVW were typically 3.5% and 12% higher than that of CVW, respectively. In constant-speed driving, the fuel efficiency of HVW was higher than that of CVW. Further research is required to analyze the exhaust gas data.

• Journal of IKEEE
• /
• v.24 no.1
• /
• pp.33-39
• /
• 2020

In this paper, we propose the design technique of the vehicle's load weight measuring system using tire pressure, which is one of the physical elements of tires. The proposed technique consists of four processes: noise correction by load and vibration, gas flow correction, data mixer and weight conversion. Noise correction by load and vibration eliminates noise that increases the tire's internal pressure due to external shocks and vibrations produced by the vehicle while it is in motion. In the gas flow correction process, the noise of the internal pressure of the tire is increased due to the temperature rise of the ground with respect to the data obtained through the noise correction process due to the load and vibration. In the data mixer process, the load and pressure on the tolerances the empty, median and the full load are classified according to the change in pressure of the tire that is delivered perpendicular to the tire in the event of cargo. In the weight conversion process, weight is expressed by weight through weight conversion algorithms using noise correction results by load and vibration and gas flow correction. The weight conversion algorithm calculates the weight conversion factor, which is the slope of the linear function with respect to the load and pressure change, and converts the weight. In order to evaluate the accuracy of the loading weight measurement system of the vehicle using the tire pneumatic system technique proposed in this paper, we propose the design technique of the vehicle's load weight measuring system using tire pressure, which is one of the physical elements of tires.. Noise correction results by load and vibration and gas flow data correction results showed reliable results. In addition, repeated weight precision test showed better weight accuracy than the standard value of 90% of domestic companies.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.13 no.6
• /
• pp.135-141
• /
• 2005

Currently many safety assessment tests are conducted by crashing a vehicle against a rigid or deformable barrier. It is quite rational to evaluate crash performance of a vehicle in a barrier test in terms of vehicle stiffness and strength. However, there has been a lot of debate on whether barrier testing is a duplicate of real world crash collisions. One of the issues is car to car compatability. There are two essential subjects in compatability. One is partner-protection when crashing into another vehicle and the other is self-protection when struck by another vehicle. When considering a car to car frontal crash between a mini car and a large heavy car, it is necessary to evaluate human body stiffness of each vehicle. In this study, in order to evaluate the compatability of cars in car-to-car crashes, four tests were conducted. Test speed of each car is 48.3km/h, and the overlap of the mini and large car is $40\%$, and the overlap of the small cars is $100\%$. In all tests, only a drive dummy is used. The test results of the car to car crash test show that vehicle safety standard of mini car is not satisfied compared with large heavy car and HIC value of mini car is higher than large car. In this case observed that the relatively lower stiffness and weight of the mini car resulted in absorbing a large share of the total input energy of the system when crashed into the large heavy car.