• 한국자동차공학회논문집
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• 제6권1호
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• pp.73-79
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• 1998

For the design and development of the wheel type excavator, the dynamic effects of travelling on the performance of the equipment should be first analyzed and conside- red in the initial design stage. In order to test the durability of the equipment in a short period, th travelling test should be performed over accelerated durability test tracks. which is more severe than general field roads such as city road, paved road, unpaved road and rough road. In this paper, a parametric study is performed in order to determine important design parameters of durability test track of a wheel type excavator. A rigid body model is developed using DADS and dynamic analysis is performed for the equipment travelling over several test roads with different severity. A comparison of test and analysis results is also presented.

• International Journal of Automotive Technology
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• 제6권4호
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• pp.351-357
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• 2005

Development of a real-time simulation model for high-speed and multibody tracked vehicles is difficult because they involve hundreds of highly nonlinear equations. In the development of a reliable tracked vehicle model for real-time simulation, it is helpful to use an off-line tracked vehicle model developed by considering all the degrees of freedom of each element. This paper presents a step-by-step procedure for the development of a real-time simulation model based on the off-line tracked vehicle model. The road input data, Profile IV, is used for the real time simulation and simulation results are compared with vehicle test results obtained in the military test field. It is noted that the simulation results are quite close to the test results.

• 한국자동차공학회논문집
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• 제12권4호
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• pp.94-100
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• 2004

A dynamic finite element analysis of a rig test model for truck chassis systems is conducted to establish an appropriate model designed to predict the fatigue life. A reference Belgian road input, which has been obtained from a field test, is imposed on the finite element model in the modal finite element analysis, and the resulting strain history is employed for the prediction of the fatigue life. This is compared with the prediction based upon the strain history measured in the field test. The two agree with each other within the limitation of the field data and the input data to the model. The high frequency responses over 50 Hz are confirmed to be negligible as far as their effect on the fatigue life is concerned.

• Geomechanics and Engineering
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• 제35권5호
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• pp.511-523
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• 2023

Canal-side roads frequently collapse due to an unexpectedly greater soft-clay thickness with a rapid drawdown situation. This causes annually increased repair and reconstruction costs. This paper aims to explore the effect of soft-clay thickness on the failure in the canal-side road in the case study of Phra Nakhon Si Ayutthaya rural road no. 1043 (AY. 1043). Before the actual construction, a field vane shear test was performed to determine the undrained shear strength and identify the thickness of the soft clay at the AY. 1043 area. After establishing the usability of AY. 1043, the resistivity survey method was used to evaluate the thickness of the soft clay layer at the failure zone. The screw driving sounding test was used to evaluate the undrained shear strength for the road structure with a medium-stiff clay layer at the failure zone for applying to the numerical model. This model was simulated to confirm the effect of soft-clay thickness on the failure of the canal-side road. The monitoring and testing results showed the tendency of rapid drawdown failure when the canal-side road was located on > 9 m thick of soft clay with a sensitivity > 4.5. The result indicates that the combination of resistivity survey and field vane shear test can be successfully used to inspect the soft-clay thickness and sensitivity before construction. The preliminary design for preventing failure or improving the stability of the canal-side road should be considered before construction under the critical thickness and sensitivity values of the soft clay.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2010년도 춘계 학술발표회
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• pp.1164-1171
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• 2010

Korea is considered to be a seasonal frozen soil area that is thawed in the spring, and most of the area is frozen in winter as to the characteristic of geography. In the current design codes for anti-freezing layer, the thickness of anti freezing layer is calculated by freezing depth against the temperature condition. Therefore, they have a tendency of over-design and uniform thickness without the considerations of thermal stability, bearing capacity and frost susceptibility of materials. So, it is essential for studying the appropriateness and bearing capacity besides the seasonal and mechanical properties of pavement materials to take a appropriate and reasonable design of the road structure. In this research, the evaluation of frost susceptibility on subgrade, ant-freezing layer, sub base was conducted by means of the mechanical property test and laboratory field road model downed scale experiment. The temperature, heaving amount, heaving pressure and unfrozen water contents of soil samples, the subgrade, anti-freezing layer, sub base soils of highway construction site, were measured to determine the frost susceptibility.

• 한국ITS학회 논문지
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• 제13권4호
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• pp.48-56
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• 2014

유류소모량 산정 모형 개발을 위해서는 차종, 도로의 경사, 포장상태, 포장종류 등 다양한 변수들을 고려해야 하지만 현재 사용하고 있는 국토교통부의 투자평가지침에도 차종으로만 구분이 되어 있을 뿐 다양한 요인들을 고려하지 못하고 있는 실정이다. 본 연구에서는 도로의 경사도가 승용차의 유류소모량에 미치는 영향을 분석하기 위해 실제 주행실험을 통해 얻은 데이터를 기반으로 유류소모량 산정 모형을 개발하고 적용성을 검증하는 것을 목적으로 한다. 경사도에 따른 유류소모량 모형 개발을 위해 GPS 장비와 연비측정장비를 이용하여 실제 주행실험을 통해 유류소모량을 초(sec)단위로 측정하였다. 평지(${\pm}0{\sim}2%$), 오르막(+2~5%), 내리막(-2~5%)의 세 가지 경사도로 구분하였으며 차량의 속도와 유류소모량을 변수로 하는 회귀모형을 이용하여 모형을 개발하였다. 승용차의 유류소모량은 내리막, 평지, 오르막 순으로 커지는 것을 확인할 수 있었다.

• 한국지반공학회논문집
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• 제26권7호
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• pp.71-80
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• 2010

지리학적 특성으로 국내는 계절 동토지역으로 겨울철에는 동상현상이 발생하고 봄철에는 지반이 해빙된다. 도로는 다양한 재료와 단면으로 구성된 구조물이기 때문에 환경성과 재료 물성뿐만 아니라 포장체 각 층의 구조적 적정성 또는 지지력을 파악하는 것이 무엇보다 중요하다. 현재 기존 동상방지층 설계법에 따르면, 동상방지층은 포장체의 구조적 적정성과는 무관하게 온도조건에 따른 동결깊이에 따라 일률적으로 결정되고 있다. 이러한 동결깊이를 포장구조설계에 적용함으로써 포장의 과다설계 우려가 있다. 따라서 본 논문에서는 노상층, 동상방지층, 보조기층의 역학적 실험을 실시하여 동상민감성을 판단하고 실규모 현장도로 모형축소 실험을 실시하였다. 동상민감성을 판단하기 위하여 토층별 온도, 동결팽창량, 부동수분 및 동결깊이를 측정하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.11-16
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• 2009

Better understanding of in-situ mechanical behavior of pavement foundations is very important to predict long-term effects on the system performance of transport infrastructure. In order to do that, resilient stiffness characterization of geomaterals is needed to properly adopt such mechanistic analysis under both traffic and environmental loadings. In this paper, in situ monitoring data from KHC test road was used to analyze the non-linearity of stress conditions under traffic and moisture loadings. Then, the predicted non-linear response using finite element method with a selected constitutive model of foundation geomaterials are verified with the field data.

• 한국자동차공학회논문집
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• 제21권1호
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• pp.1-8
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• 2013

Recently, the automotive technology has developed with electronics and information technology as convergence technology while vehicles had been regarded as machines. Moreover, vehicles are becoming more intelligent and safer devices, assembly of advanced technologies by customers' demand. Even though all of installations of vehicle have attracted as diverting devices, it cause drivers' mistakes like delay of response on traffic condition. Here, we proposed the Field Operational Test (FOT) environment which could be used as driving and road conditions collector(Vehicle motion, Traffic condition, Driver input, Driver state, etc.) for researches about Driver Friendly Intelligent System(SCC, LDWS, etc.), Human Vehicle Interface(Driving Workload, etc.) and Economic Drive Model. Furthermore driving patten and fuel consumption patten of drivers were analyzed by measured data and direction of future research was suggested.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.367-374
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• 2005

In order to construct the farm road in Shi-Hwa project, coarse soils excavated from hillsides have been used as road materials for reclamation. Suitable borrow pits available in land are now limited and also they bring about environmental problems when soils are excavated at the borrow pits and transported to the site. When using fine and wet materials as fill, however, many engineering problems can be encountered. Usually, the materials have high water contents, low strength, and high compressibility. In order to use them, we need research that can improve the inherent properties of those materials. In order to tackle with the problems, researches on soil improvement involve mixing lime geo-cement to the fine wet soils. A lab model test is necessary to verify effectiveness and comparison of those techniques. A field test is also required to show applicability and to find problems that may exist in the design and construction stages.