http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
[구조강도부문] 발전설비용 고온 스터드 볼트의 교체기준 설정
정남용(N.Y. Chung),김문영(M.Y. Kim) 한국자동차공학회 2000 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
The stud bolts should be degraded more fast under high temperature(over 450 C'). Therefore, replacement cycle of stud bolts was performed with many kinds of method, which are ultrasonic test(UT), magnetic test(MT), wobble test, visual test and hardness test. Especially, the methods like wobble test have been applied to replacement criteria of stud bolt developed in manufacture company after long time operation. We applied three types of methods on the three sites and the obtained data are compared with the evaluation methods. From the results, the replacement criteria for stud bolts under high temperature of power plants were proposed.
[재료부문] 균질재의 편측 반원공에서 파생하는 혼합모드 균열에 대한 진전경로의 시뮬레이션 예측
정남용(N.Y.Chung),송춘호(C.H.Song) 한국자동차공학회 1999 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
The mixed mode cracks are occurred in uses of composite materials. bonded dissimilar materials and homogeneous materials in various industries. When these materials are used in cars. trains, aircrafts, electronic devices, engineering structures must be fastened with bolts and nuts or rivets in the holes. In this case, stress concentration occurs around the edge semicircular hole and crack will propagate from it. Cracks emanating from the hole lead to failure of structures. Therefore. it is very important to prediction of propagation angle and path for a crack emanating from a semicircular hole in a homogeneous material. In this paper, stress intensity factors and crack propagation angle and path were analyzed by boundary element method for crack emanating from an edge semicircular hole in a homogeneous material. The relations between their variations and effects were discussed,
정남용(N.Y.Chung),송춘호(C.H.Song) 한국자동차공학회 1994 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
The mixed-mode crack is generated in composite materials for fiber/matrix, bonded joint of dissimilar materials and structural reliability problems, it is required prediction for crack propagation angle and path.<br/> In this paper, the prediction for crack propagation angle and path were simulated numerically by using boundary element method and investigated experimentally by static test. The numerically simulated results by boundary element method were in good agrement with experimental results. On the base of obtained results, stress intensity factor, relation between crack length and angle of slant crack and crack propagation path are discussed<br/>
정남용(N.Y.Chung),김희송(H.S.Kim),김기성(K.S.Kim) 한국자동차공학회 1995 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1995 No.6_2
Increasing use of ceramics/metal bonded joints is required to analyze about the residual stress distribution and stress singularity at an interface edge for its bonded joints.<br/> In this paper, the residual stress distribution and stress singularity index for the ceramics/metal bonded joints were analyzed by using 2-dimensional elastic boundary element method.<br/> And it was also investigated about the variations of residual stress distribution and stress singularity index by changes for the combinations of ceramics/metal, thickness of interlayer and temperatures for ceramics/metal bonded joints.<br/>
이종접합재의 원공에서 파생하는 계면균열에 대한 응력세기계수의 해석
정남용(N.Y.Chung),송춘호(C.H.Song) 한국자동차공학회 1997 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1997 No.6_2
Applications of bonded dissimilar materials in the fields of industries such as cars, aircrafts, electronic devices and engineering structures are very increasing. When the uses of bonded dissimilar materials which must fasten the structures with bolts and nuts or rivets in the holes, stress concentration occurs around the hole on the bonded interface and it causes crack initiation and catastrophic failure. Therefore, it is very impotant that analyze stress intensity factors for interface cracks emanating from circular holes in bonded dissimilar materials.<br/> In this paper, stress intensity factors by boundary element method for interface cracks emanating from a circular hole and semicircular hole in bonded dissimilar materials were analyzed, and relations between therir variations and effects were discussed.<br/>
김기성(K. S. Kim),김희송(H. S. Kim),정남용(N. Y. Chung) 한국자동차공학회 1996 한국자동차공학회 춘 추계 학술대회 논문집 Vol.1996 No.11_1
In this paper, a method to analyze an interface crack under both residual stresses and applied loading was proposed, and some results of boundary element method(BEM) analysis were presented. The bonding strengths of Si₃N₄/metal joints with an interface crack were examined, and the stress intensity factors of these joints were analyzed by BEM. Also crack propagation direction was numerically simulated by using BEM. Crack propagation angle was able to easily determine based on the maximum stress concept Moreover, a simulation analysis of the fracture angle was presented and the results were compared with those of the experiments. The predidtion of fracture strength by the fracture toughness of the Si₃N₄/metal bonded joints were proposed.<br/>
정남용(N.Y.Chung),이원(W.Yi),정의섭(E.S.Jeong) 한국자동차공학회 1994 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-
Recently, the widespread use of dissimilar materials in metal/ceramics, resin/metal, IC package, coating, brazing and soldering which is required bonded strength evaluation at the interface edge of bonded joint in dissimilar materials.<br/> In this paper, the stress distribution and stress singularity of single-lap joint in dissimilar materials were investigated analytically by the bogy's solution and numerically by using boundary element method, The numerically calculated results of the stress singularity by boundary element method were in good agreement with Bogy's analytical solution. On the basis of the obtained results, the effects of dissimilar materials combinations. bonded length and fillet angle at the interface edge are discussed.