http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : 박경동(Kyungdong Park) (검색결과 3 건)
- 무료
- 기관 내 무료
- 유료
-
박경동(Kyungdong Park),진영범(Youngbeom Jin) 한국자동차공학회 2004 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
The lightness of components required in automobiles and machinery industry is requiring high strength of components. In particular, manufacturing process and new materials development for solving the fatigue fracture problem attendant upon high strength of suspension of automobile are actively advanced. In this paper, the effect of compressive residual stress of spring steel by shot peening on fatigue crack growth characteristics in environmental with stress ratio(R=0.1, R=0.3, R=0.6)were investigated with considering fracture mechanics. By using the methods mentioned above, I arrived at the following conclusions: (1) The fatigue crack growth rate(da/dN)of the shot peening material was lower than the unpeening material. And in stage Ⅰ, △Kth, the threshold stress intensity factor, of the shot peening is high in critical parts unlike the unpeening material. (2) Fatigue life shows more improvement in the shot peening material than in the unpeening material. And compressive residual stress of surface on the shot peening processed operate a rsistance of fatigue crack propagation.
-
박경동(Kyungdong Park),정재욱(Jaewook Jung) 한국자동차공학회 2003 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
The order of the fracture toughness in case of unpeened specimens was observed as R.T > 100℃ > -60℃ > 200℃ > -100℃ Because of the low temperature embrittlemnt, the decreasing range of fracture toughness is high as overall tendency. The order of fracture toughness of shot peened specimens was respectively shown as 200℃ > 100℃ > R.T > -60℃ > -100℃. There is a difference between shot peened specimen and unpeened specimen. Specially, the shot peened specimens show the higher decreasing of fracture toughness by the low temperature brittleness. Fracture toughness of shot peened metal was lower than that of unpeened metal. It is thought thai it should be bacause, in fracture toughness experiment, it is accompanied with large scale yielding and it is carried out at the stress of crack tip as relieved by the pre-crack, and then the effect of tensile residual stress was disappeared. And also it can be considered it should be decreasing the fracture toughness on account of the brittle fracture by the surface hardening.<br/>
-
표면처리법에 따른 SUP-9/50CrV₄의 부식특성에 관한 연구
정재욱(Jaewook Jung),박경동(Kyungdong Park) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.11
In this study, the high strength and superior roughness spring sleets as the suspension material, used for automobile and railroad industries were utilized to carry out die following investingations. Corrosion times were controlled in 7,14,30 and 60days to examine the relation between corrosion pit and compressive residual stress in the static corrosion environment after shot peened. And then corrosion current and corrosion potential were measured for every 24 hours to investigate the corrosion mechanism. Shot peened material shows tile low or rate of corrosion current as compared with unpeened material. In case of hot peened material which has the highest residual stress. it has a low corrosion current density.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
