• 콘크리트학회지
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• 제14권4호
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• pp.33-39
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• 2002

레미콘의 품질성능을 좌우하는 것은 콘크리트 사용재료 및 배합뿐만 아니라 레미콘을 제조하는 믹서 및 이를 현장까지 운반하는 트럭 에지테이터의 품질성능에 크게 좌우된다. 그러나, 레미콘 공장의 혼합 설비인 믹서 및 트럭 에지테이터에 관한 국내 자료는 거의 전무한 실정이며 이에 관한 연구도 상대적으로 매우 부족하다. 특히, 최근에는 고강도 콘크리트, 고유동 콘크리트, 고강도 경량 콘크리트, 수중불분리 콘크리트, 섬유보강 콘크리트 등 고성능 콘크리트 성능에 대한 요구가 날로 증가하는 추세이며 이에 따라 레미콘 공장에서도 혼합설비 및 운반설비가 고성능화 되어 가는 추세이다.(중략)

• 한국전산구조공학회논문집
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• 제33권3호
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• pp.187-192
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• 2020

덤프 트럭 데크의 경량화를 통한 연료 소비를 줄이고 에코 친화적인 설계를 위해서는 정확한 구조 분석이 필요하다. 지금까지 데크의 하중은 정수압 또는 토압 이론을 기반으로 계산되었다. 이 방법으로 데크의 하중 불균일을 계산할 수 없다. 하중 분포는 골재 입자의 크기 분포 및 상호 작용에 따라 달라진다. 이산요소법은 유한요소법보다 효과적으로 골재의 거동을 시뮬레이션할 수 있다. 본 논문에서는 벌크 밀도와 안식각을 측정하여 주요 특성을 얻었다. 15톤 덤프 트럭 데크는 범핑, 브레이킹 및 회전 시의 운동 조건을 적용하여 얻은 하중을 사용했다. 시뮬레이션은 이산요소해석 소프트웨어인 EDEM을 사용했다. 데크의 응력 및 변형 분포는 NASTRAN에 의해 계산되었다. 측정된 값과 비교하였고, 이를 통해 DEM 시뮬레이션의 결과는 수학적 가정에 의한 결과보다 정확함을 확인하였다.

• 한국지반환경공학회 논문집
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• 제16권2호
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• pp.15-25
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• 2015

경량기포혼합토는 운반 과정에서 재료의 물성이 변화하므로, 시공 시의 성질이 설계 품질을 만족하는지를 확인할 필요가 있다. 본 연구는 현장시험을 통해 믹스트럭 운반에 의한 재료특성의 변화를 분석하는데 목적이 있다. 현장시험에 사용된 경량기포혼합토는 단위중량 $9.0{\pm}1.0kN/m^3$, 흐름값 $190{\pm}20mm$로 제작되었다. 재료특성의 변화를 분석하고자 운반 전 후 시료의 단위중량과 흐름값을 측정하고, 일축압축강도 시험을 실시하였다. 교반시간은 19~175분으로 다양화하였다. 시험결과 경량기포혼합토는 교반에 의해 단위중량, 흐름값과 일축압축강도는 변화하나 품질관리기준은 만족하였다. 운반 후 단위중량과 흐름값의 평균 변화량은 $(+)0.10kN/m^3$, 4.8mm로 교반시간에 따른 단위중량과 흐름값의 평균변화량은 일정하였다. 28일 일축압축강도는 $20{\sim}150kN/m^2$ 증가하나 변화량과 교반시간과의 관계는 명확하지 않았다. 결론적으로 175분 이내에서의 운반에 의한 물성의 변화는 적으므로 적용에 문제는 발생하지 않을 것으로 생각된다.

• 한국자동차공학회논문집
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• 제20권6호
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• pp.107-116
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• 2012

In this study, the trucks(2.9-liter) have been developed to use DME as fuel, and performance test of the vehicle's DME engine, power, emissions, fuel economy and vehicle aspects was conducted. For experiments, the fuel system(common-rail injectors and high-pressure pump included) and the engine control logic was developed, and ECU mapping was performed. As a result, the rail pressure from 40MPa to approximately 65% increase compared to the base injector has been confirmed that. Also, the pump discharge flow is 15.5 kg/h when the fuel rail pressure is 400rpm(40MPa), and the pump discharge flow is 92.1 kg/h when the fuel rail pressure is 2,000rpm(40MPa). The maximum value of full-load torque capability is 25.5 kgfm(based on 2,000 rpm), and more than 90% compared to the level of the diesel engine were obtained. The DME vehicle was developed in this study, 120 km/h can drive to the stable, and calculated in accordance with the carbon-balance method of fuel consumptions is 5.7 km/L.

• 융복합기술연구소 논문집
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• 제2권1호
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• pp.24-30
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• 2012

In this study, the trucks(2.9-liter) have been developed to use DME as fuel, and performance test of the vehicle's DME engine, power, emissions, fuel economy and vehicle aspects was conducted. For experiments, the fuel system(common-rail injectors and high-pressure pump included) and the engine control logic was developed, and ECU mapping was performed. As a result, the rail pressure from 40MPa to approximately 65% increase compared to the base injector has been confirmed that. Also, the pump discharge flow is 15.5 kg/h when the fuel rail pressure is 400rpm(40 MPa), and the pump discharge flow is 92.1 kg/h when the fuel rail pressure is 2,000rpm(40MPa). The maximum value of full-load torque capability is 25.5kgfm(based on 2,000rpm), and more than 90% compared to the level of the diesel engine were obtained. The DME vehicle was developed in this study, 120 km/h can drive to the stable, and calculated in accordance with the carbon-balance method of fuel consumptions is 5.7 km/L.

• 한국기계가공학회지
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• 제17권3호
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• pp.127-133
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• 2018

To reduce fuel consumption, research on the weight reduction of vehicles is being actively carried out. Researchers have typically tried to replace metal materials with composites materials, but these materials did not satisfy the required strength and rigidity of a vehicle. Composites are usually not used because of their high cost. There are incomplete studies on lightweight trucks that transport cargo. Therefore, in this paper, we enhance the lightness and mechanical strength through design optimization of the deck frame for a lightweight truck. For that purpose, the side member and cross member, which are mounted on the lower part of the truck to assure the safety of the vehicle and support the luggage load, were targeted. The result of numerical analysis on the safety of the frame was obtained by changing the shape of each cross-section. To verify the numerical analysis, we compared it with the theoretical value of a cantilever beam. As a result, the suitability of the cross-sectional shapes of each frame was confirmed through numerical analysis.

• 한국자동차공학회논문집
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• 제16권6호
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• pp.58-64
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• 2008

An aluminum radius rod using rheo-forging method has been developed for heavy commercial vehicles to decrease vehicle unsprung weight. To design the shape of the rod, structural simulations are performed using two load cases. To evaluate durability performance of the rods, a test system which has simultaneous 3 axes actuating system is developed. And 3 axes durability test conditions are established based on vehicle field tests. Using the test systems and the conditions, the durability test is carried out and the rods have passed the test conditions of 700,000 cycles. The weight of a developed aluminum radius rod is 4.2kg and it was drastically reduced by 48.8 percent in comparison with the weight of a steel radius rod.

• 한국생산제조학회지
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• 제21권2호
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• pp.344-348
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• 2012

The knuckle crane design in Korea has been performed by assuming a cantilever beam type structure and numerically analyzing design data and finally improving the stiffness by replacing material. In our study, a complete finite element model of the knuckle crane is constructed and finite element analysis is conducted using Optistruct. Structural optimization to reduce the weight of the knuckle crane is processed by applying maximum loading condition at the largest radius of motion, which is the worst case of loading condition. As the results, existing over stiff design in a knuckle crane is corrected to meet a desired design limit and overall weight is reduced, which eventually leads to a reduction of $CO_2$ emission.

• 기계저널
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• 제28권1호
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• pp.23-27
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• 1988

4WD차의 특성은 출력이 뛰어남은 물론, 고속안정성을 추구하고 있으며, 견고한 차체로 이루어져 하물적재능력도 뛰어난 이른바 전천후 자동차라고 말할 수 있다. 4WD의 두드러진 특성은 전 시중 지프의 활약에서 나타났듯이 황무지, 사막 및 비포장도로에서의 주행능력이 우수한 것은 말할 것도 없으며 트럭 등에 이용되면서부터는 하물적재에 따른 주행능력의 감소도 극복하게 되 었다. 더욱이 오늘날에는 자동차에 대한 욕구가 다양해짐에 따라 각국에서는 고출력을 선호 하는 시대적 요구에 부응하여 미끄러운 노면에서의 안정주행 및 포장도로상에서의 고속안정성을 겸비한 4WD 차종의 개발을 서두르고 있다. 4WD 차는 기존 자동차의 능력을 확대시켜 노면의 조건에 구애받지 않고 자유롭게 주행할 수 있는 전천후 자동차로 개발되기는 하였지만 이에 따 르는 소음, 연비, 에너지 손실 등의 문제가 완전히 해결된 것은 아니다. 또한 악조건 상에서 운 행하는 만큼 차체의 경량화, 기관의 소형화 및 균형유지 등의 제반 사항을 해결하기 위해서도 노 력을 기울이지 않으면 안된다.

• 소성∙가공
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• 제32권1호
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• pp.12-19
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• 2023

The armature core is a part responsible for the skeleton of the steering wheel. Currently, in the case of commercial trucks, the main parts of the parts are manufactured separately and then the product is produced through welding. In the case of this production method, quality and cost problems of the welded parts occur, and an integrated armature core made of magnesium alloy is used in passenger vehicles. However, in the case of commercial trucks, there is no application case and research is insufficient. Therefore, this study aims to develop an all-in-one armature core that simultaneously applies a magnesium alloy material and a die casting method to reduce the weight and improve the quality of the existing steel armature core. The product was modeled based on the shape of a commercial product, and finite element analysis (FEA) was performed through Ls-dyna, a general-purpose analysis program. Through digital image correlation (DIC) and uniaxial tensile test, the accurate physical properties of the material were obtained and applied to the analysis. A total of four types of compression were applied by changing the angle and ground contact area of the product according to the actual reliability test conditions. analysis was carried out. As a result of FEA, it was confirmed that damage occurred in the spoke area, and spoke thickness (t_spoke), base thickness (t_base), and rim and spoke connection (R) were designated as design variables, and the total weight and maximum equivalent stress occurring in the armature core We specify an objective function that simultaneously minimizes . A prediction function was derived using the sequential response surface method to identify design variables that minimized the objective function, and it was confirmed that it was improved by 22%.