차 대 보행자 사고에서 보행자 전도 거리에 영향을 주는 인자에 관한 연구

강대민(DaeMin Kang),안승모(SeungMo Ahn) 한국자동차공학회 2007 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

The fatalities of pedestrian account for about 40.0% of all fatalities in Korea 2005. Vehicle-Pedestrian accident generates trajectory of pedestrian. The throw distance of pedestrian can be influenced by many variables. The variables that influence trajectory of pedestrian can be classified into vehicular factors, pedestrian factors, and road factors. The trajectory of pedestrian, dynamic characteristics of multi-body were analyzed by PC-CRASH, a kinetic analysis program for a traffic accident. PC-CRASH enables an analyst to investigate the effect of many variables. Based on the results, the variables that influence trajectory of pedestrian were vehicular frontal shape, vehicular impact speed, the offset of impact point, the height of pedestrian, friction coefficients of pedestrian. However the weight of pedestrian did not affect trajectory of pedestrian considerably.

AZ31 마그네슘 합금의 고온 특성 및 크리이프 변형기구에 관한 연구

강대민(Daemin Kang),안정오(Jungo An) 한국동력기계공학회 2004 한국동력기계공학회 학술대회 논문집 Vol.- No.-

Magnesium alloys have been widely used for many structural components of automobiles and aircraft because of high specific strength and good cast-ability in spite of hexagonal closed-packed crystal structure of pure magnesium. In this study, unaxial tension tests at high temperature and creep tests are done in order to investigate the characteristic of high temperature and mechanism for creep deformation of AZ31 Mg alloy. Yield stress and ultimate tensile stress decreased with increasing temperature, but elongation increased from results of uniaxial tension test at high temperature. The apparent activation energy Qc and the applied stress exponent n, rupture life have been determined during creep of AZ31 Mg alloy over the temperature range of 200℃ to 300℃ and stress range of 2.39 kgf/㎟ to 9.55 kgf/㎟, respectively, in order to investigate the creep behavior. Constant load creep tests were carried out in the equipment including automatic temperature controller, whose data are sent to computer. At around the temperature of 200℃~220℃ and under the stress level of 6.37~9.55㎏f/㎟, and again at around the temperature of 280℃~300℃ and under the stress level of 2.39~3.98kgf/㎟, the creep behavior obeyed a simple power-law relating steady state creep rate to applied stress and the activation energy for the creep deformation was nearly equal and, a little low, respectively, to that of the self diffusion of Mg alloy including aluminum. Also they were tan obtained rupture surfaces at high temperature have bigger dimples than those at lower temperature by S.E.M.

어린이용 자전거의 차량 충돌특성

강대민(DaeMin Kang),안승모(SeungMo Ahn),박경도(KyoungDo Park) 한국자동차공학회 2011 한국자동차공학회 부문종합 학술대회 Vol.2011 No.5

Recently the usage of bicycle has increased steeply in Korea owing to traffic culture of well-being. In car to bicycle accident, the throw distance of bicycle is very important factor for reconstructing of the accident. The variables that influence on the throw distance of bicycle can be classified into the factors of vehicle, bicycle and road condition. Simulations and collision tests in actual car to bicycle accident were executed for obtaining throw distance of bicycle. The simulations was executed by PC-CRASH™ and for actual crash tests sand bags were used for the behavior of bicyclist instead of dummy. Factors considered were vehicle velocity and the moving angles of bicycle, also bicycle and vehicle type were fairy cycle and automobile. The results of simulation and test are expected as very useful things for predicting the collision behavior in car to bicycle accident.

차 대 보행자 충돌시 사고해석 모델개발

강대민(DaeMin Kang),안승모(SeungMo Ahn),안정오(JungO An) 한국자동차공학회 2010 한국 자동차공학회논문집 Vol.18 No.3

The fatality of pedestrian accounts for about 21.2% of all fatality at 2007 year in Korea. In car to pedestrian accident it is very important to inspect the throw distance of pedestrian after collision for exact reconstructing of the accident . The variables that influence on the throw distance of pedestrian can be classified into the factors of vehicle and pedestrian, and road condition. It was simulated by PC-CRASH, a kinetic analysis program for a traffic accident in sedan type vehicle and SPSS program was used for regression analysis. From the results, the throw distance of pedestrian increased with the increasing of vehicle velocity, and decreased with the increasing of impact offset. Also it decreased with the increasing of velocity of pedestrian at accident, and throw distance at the road condition of wet was longer than that at dry condition. Finally, the regression model of sedan type vehicle on the throw distance of pedestrian was as follows; dist<SUB>i</SUB>=2.39-0.11offset<SUB>i</SUB>+0.59speed<SUB>i</SUB>-5.45height<SUB>i</SUB>-0.25walk<SUB>i</SUB>+2.78wet<SUB>i</SUB>+e<SUB>i</SUB>

AZ31마그네슘합금의 프레스포징시 FE해석

황종관(Jongkwan Hwang),강대민(Daemin Kang) 한국자동차공학회 2006 한국 자동차공학회논문집 Vol.14 No.1

Magnesium alloys have been widely used for many structural components of automobiles and aircraft because of high specific strength and good castability in spite of hexgonal closed-packed crystal structure of pure magnesium. In this paper, FE analysis was executed about the formability of AZ31 magnesium alloy on press forging process. For this, the variation of sheet temperature, distribution of punch force and the effect of heat transfer and friction between punch and sheet on the forming characteristics during press forging of AZ31 has been analyzed by finite element analysis. In order to obtain temperature dependence of material characteristics, uniaxial tension tests at elevated temperature were done under temperature of 100℃ ~ 500℃.

AZ31 마그네슘 합금의 크리이프 특성에 관한 연구

안정오(Jungo An),강대민(Daemin Kang) 한국자동차공학회 2004 한국자동차공학회 지부 학술대회 논문집 Vol.- No.-

The apparent activation energy Qc and the applied stress exponent n, rupture life have been determined during creep of AZ3l Mg alloy over the temperature range of 200℃ to 300℃ and stress range of 2.39 kg/㎟ to 9.55 kg/㎟, respectively, in order to investigate the creep behavior. Constant load creep tests were carried out in the equipment including automatic temperature controller, whose data are sent to computer.<br/> At around the temperature of 200℃~220℃ and under the stress level of 6.37~9.55kg/㎟, and again at around the temperature of 280℃~300℃ and under the stress level of 2.39~3.98kg/㎟, the creep behavior obeyed a simple power-law relating steady state creep rate to applied stress and the activation energy for the creep deformation was nearly equal and, a little low, respectively, to that of the self diffusion of Mg alloy including aluminum.<br/> From the above facts, at around the temperature of 200℃~220℃ the creep deformation for AZ31 Mg alloy seemed to be controlled by dislocation climb but controlled by dislocation glide at 280℃~300℃.

AZ31 마그네슘 합금의 고온 크리이프 변형특성에 관한 연구

안정오(Jungo An),강대민(Daemin Kang),구양(Yang Koo),심성보(Sungbo Sim) 한국자동차공학회 2005 한국 자동차공학회논문집 Vol.13 No.3

The apparent activation energy Qc, the applied stress exponent n, and rupture life have been determined from creep test results of AZ31 Mg alloy over the temperature range of 200℃ to 300℃ and the stress range of 23.42 M Pa to 93.59 MPa, respectively, in order to investigate the creep behavior. Constant load creep tests were carried out in the equipment including automatic temperature controller with data acquisition computer.<br/> At the temperature of 200℃-220℃ and under the stress level of 62.43-93.59 MPa, and at around the temperature of 280℃-300℃ and under the stress level of 23.42-39.00 MPa, the creep behavior obeyed a simple power-law relating steady state creep rate to applied stress and the activation energy for the creep deformation was nearly equal to that of the self diffusion of Mg alloy including aluminum<br/> From the above results, at the temperature of 200℃-220℃ the creep deformation for AZ31 Mg alloy seemed to be controlled by dislocation climb but controlled by dislocation glide at 280℃-300℃. And relationship between rupture time and stress at around the temperature of 200℃-220℃ and under the stress level of62.43-93.59 MPa, and again at around the temperature of 280℃-300℃ and under the stress level of 23.42-39.00 MPa, respectively, appeard as follow;<br/> logσ=-0.18(T+460)(logtr+21)+5.92, logσ=-0.25(T+460)(logtr+21 )+8.02<br/> Also relationship between rupture time and steady state creep rate appears as follow; Inε = -0.88lntr-2.45

LMD 금형커팅 내구성 평가

김원혁(Wonhyuck Kim),전형준(Hyeongjun Jeon),강대민(Daemin Kang) 한국자동차공학회 2018 한국자동차공학회 부문종합 학술대회 Vol.2018 No.6

마그네슘합금의 이종 마찰교반접합시 용접변수의 영향

박경도(Kyongdo Park),이해진(Haejin Lee),강대민(Daemin Kang) 한국자동차공학회 2018 한국자동차공학회 부문종합 학술대회 Vol.2018 No.6

AISI M2 파우더를 이용한 레이저 메탈 디포지션의 트랙 특성 분석

김원혁(WonHyuck Kim),송명환(MyungHwan Song),박인덕(InDuck Park),강대민(DaeMin Kang) 한국자동차공학회 2016 한국 자동차공학회논문집 Vol.24 No.4

In this paper, the characteristics analysis of LMD track, such as including track structure, track wear resistance and track thickness, were analyzed to enhance the deposition efficiency using a diode-pumped disk laser. SKD61 hot work steel plate and Fe based AISI M2 alloy were used as a the substrate and powder for the LMD process, respectively. The laser power, track pitch and powder feed rate among LMD parameters were adopted to estimate the deposition efficiency. As the laser power is increased, heat input and melting pool on the substrate is grown also increases, so resulting in the increased LMD track thickness was increased. Through EPMA mapping analysis of the cross-section in the LMD track, it was observed that all the elements are evenly distributed inside. Therefore, the entire hardness in the LMD track is expected to be almost uniform regardless of location. The characteristics of the LMD specimen were excellent compared to the STD11 specimen in terms of the wear track width and the wear rate as well as the coefficient of friction. Especially the wear rate of LMD specimen has been significantly reduced by 60 % or more. From Based on the experimental results, the prediction formula of LMD thickness was calculated by using laser power, track pitch and powder feed rate.