튜브 프레팅마멸 분석을 위한 미끄럼변위 해석방법 개선

송주선(Ju-Sun Song),김형규(Hyung-Kyu Kim),이영호(Young-Ho Lee),김재훈(Jae-Hoon Kim) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.11

Fundamentally, slip displacement should be known to solve the problem related to the fretting wear. For this, methods for measuring the slip displacement range in the contact surface of the tube and the supports were introduced and analyzed in this study. Also the increment of the slip displacement during a cycle was calculated using the revised formulas. As a result, the slip displacement newly evaluated was much higher (7~50 times) than that previously evaluated especially in the case of the gap existence. This enables to explain the severe wear found when there was a gap between the tube and the supports.

튜브진동 시 지지부에서의 축ㆍ횡방향 미끄럼변위 분석

송주선(Ju-Sun Song),김형규(Hyung-Kyu Kim),이영호(Young-Ho Lee),김재훈(Jae-Hoon Kim) 대한기계학회 2004 대한기계학회 춘추학술대회 Vol.2004 No.4

Slip displacement is brought into focus to study the tube fretting wear that occurs on the contact by the springs. An oscillating tube was in contact with plate support springs. The contact condition was varied as normal force 5 N, and gaps of 0.1 and 0.2 ㎜ in the experiment. The oscillation range of the tube was also varied as 0.2, 0.3, 0.4 and 0.7 ㎜. Formulas for predicting the slip displacement range were derived in terms of the vibration amplitudes measured during the tube oscillation. It was found that the slip displacement in transverse direction was much higher (720~33000 times) than that in axial one. This resulted in the severer wear on the contact suffered from transverse slip.

튜브 프레팅마멸 연구를 위한 접촉부 미끄럼 거동의 실험적 분석

송주선(Ju-Sun Song),김형규(Hyung-Kyu Kim),이영호(Young-Ho Lee),김재훈(Jae-Hoon Kim) 한국트라이볼로지학회 2004 한국트라이볼로지학회 학술대회 Vol.38 No.-

To study the fretting wear problem of a nuclear fuel, the behaviour of slip displacement at the contact is investigated in this paper. The slip displacement was evaluated from the vibration amplitudes measured during a fretting wear experiment in real time basis. The experiment was conducted in air at room temperature and one span of a fuel assembly was simulated. The contact condition between the grids and rods varied as the normal force of 5 N and gap of 0.2 ㎜. The fuel rod was vibrated with the frequency of 30 ㎐ and the center oscillation of 0.7 ㎜. Simple geometrical equations were used for the axial and transverse slip displacement. The trace of rod movement was investigated, which was affected by the contact condition. The vibration characteristic was not altered during the experiment when a specific contact condition was applied. The severest wear on the rod occurred in the case of axial slip and gap existence. It implies that the mechanism of impact wear should be understood for studying the fuel fretting problem.

고온고압수중에서 접촉형상에 따른 마멸거동 분석

송주선(Ju-Sun Song),김형규(Hyung-Kyu Kim),이영호(Young-Ho Lee),김재훈(Jae-Hoon Kim) 한국트라이볼로지학회 2004 한국트라이볼로지학회 학술대회 Vol.39 No.-

In this paper, fretting wear tests were conducted in air at room temperature (RT) and in water at high temperature and high pressure (HTHP) environment to analyze the wear characteristic. As for the supporting condition between the tube and spring/dimple, the gap of 0.2 ㎜ in air at RT and the normal force of 10 N and the slip of 50 μ m in water at HTHP were applied. Four different shapes of spring/dimple specimen (type A, B, C, D) were used. Detail eaxamination of wear scar was also performed using SEM micrographs. As a result, in the case of the spring of truncated wedge, severer wear occurs than the others. Protrusion part was found and larger in air at RT. It is thought that the difference in the wear volume and the protrusion is caused by the different wear mechanism corresponding to the different environment.

고온고압 미끄럼/충격조건에서 마멸평가 변수 연구

이영호(Young-Ho Lee),송주선(Ju-Sun Song),김형규(Hyung-Kyu Kim),정연호(Youn-Ho Jung) 한국트라이볼로지학회 2004 한국트라이볼로지학회 학술대회 Vol.39 No.-

The impact/sliding wear tests have been performed in high temperature high pressure water in order to evaluate the effect of spring shape on the wear behavior of a spring supported tube for nuclear fuel fretting study. The results indicate that the tube wear volume and the size of the wear scar are closely related to each spring shape. From the analysis of the wear scar, it is possible to extract the real worn area (Aw) from the size of the wear scar (At). In addition, we found that the wear volume has a linear relation with the real worn area rather than the size of wear scar and this was only determined by each spring shape in the high temperature and pressure water condition. From the above results, it is possible to evaluate the wear resistant spring using the correlation between the variation of the real worn area and the wear behavior at each spring.

FBN1 유전자 돌연변이가 동반된 양안 단순 수정체탈구 1예

남승완(Seung Wan Nam),송주선(Ju Sun Song),기창석(Chang Seok Ki),기창원(Chang Won Kee) 대한안과학회 2017 대한안과학회지 Vol.58 No.10

목적: 유전자 돌연변이가 확인된 양안 단순 수정체탈구 1예를 보고하고자 한다. 증례요약: 47세 여자가 1개월 전부터 발생한 우안 안통 및 시력저하를 주소로 내원하였다. 특별한 전신이상 및 외상력은 없었으나, 수정체탈구 가족력이 있었다. 내원 시 우안 안압이 45 mmHg로 상승되었고, 현성굴절검사에서 우안 근시성변화(-6.5D)를 보였으며, 우안 수정체전방불완전탈구로 인해 우안 전방각폐쇄가 관찰되었다. 이후 우안 수정체초음파유화술 및 후방인공수정체공막고정술을 시행하였고 우안 최대교정시력은 1.0, 안압은 15 mmHg로 호전되었다. 하지만 2년 뒤 좌안 간헐적 안통 및 시력저하 소견으로 재내원하였고, 좌안 수정체전방불완전탈구가 관찰되었다. 좌안 수정체초음파유화술 및 후방인공수정체공막고정술을 시행한 뒤 좌안 간헐적 안통 및 시력저하는 호전되었다. 추후 시행한 유전자 검사에서 FBN1 유전자 돌연변이가 확인되었다. 결론: 외상력이 뚜렷하지 않은 양안 수정체탈구 환자에서 전신검사 및 안과검사로 동반질환을 배제하고, 가족력을 확인해야 하며, 유전성이 의심될 경우 환자 및 가족들에게 유전자 검사를 시행하여 유전 상담 및 치료 방침 결정에 이용할 수 있다. Purpose: To report a case of bilateral simple ectopia lentis associated with FBN1 gene mutation. Case summary: A 47-year-old women presented with a one-month history of ocular pain and decreased visual acuity of the right eye. She had a family history of crystalline lens dislocation but showed no systemic abnormality or trauma history. Intraocular pressure was 45 mmHg in the right eye, which showed a myopic shift (-6.5 D). The crystalline lens of the right eye was subluxated to the anterior chamber, and the angle was closed. Phacoemulsification with scleral fixation of the posterior chamber intraocular lens of the right eye was performed. After that, best corrected visual acuity of the right eye was 1.0, and intraocular pressure was 15 mmHg. After 2 years, she presented with intermittent ocular pain and decreased visual acuity of the left eye. The crystalline lens of the left eye was subluxated to the anterior chamber. Phacoemulsification with scleral fixation of the posterior chamber intraocular lens of the left eye was performed. After that, intermittent ocular pain and visual acuity of the left eye were improved. Genetic testing confirmed an FBN1 gene mutation in the patient. Conclusions: A bilateral ectopia lentis patient without history of definite trauma should undergo complete systemic and ophthalmic examination to rule out accompanying disease, and a detailed family history should be collected. If hereditary ectopia lentis is suspected, genetic testing of probands and their family should be performed and will be helpful for genetic counseling and ophthalmic surveillance.

튜브진동 시 판스프링 지지부의 미끄럼변위와 마멸 분석

김형규(Hyung-Kyu Kim),이영호(Young-Ho Lee),송주선(Ju-Sun Song) 한국트라이볼로지학회 2003 한국트라이볼로지학회 학술대회 Vol.37 No.-

Tube oscillation behaviour is experimentally investigated for the study on the fuel rod fretting that is caused by the flow-induced vibration in nuclear reactor. The experiment was conducted in air at room temperature. The specimen of tube assembly was supported by plate springs which simulated the spacer grids and fuel rods of a fuel assembly. To investigate the influence of contact condition between the grids and rods, normal load of 10 and 5 N, gaps of 0.1 and 0.3 ㎜ were applied. The range of the oscillation at the center of the fuel rod specimen was varied as 0.2, 0.3 and 0.4 ㎜ to simulate the fuel rod vibration due to flow. Displacements near the contact were measured with four displacement sensors during the tube oscillation. As results, the shape of oscillation (phase) varied depending on the contact condition. The oscillation displacement increased considerably from the contact to gap condition. The displacement increased further as the gap size increased. It is regarded that the spring shape influences the tube oscillation behaviour. Simple calculation showed that the slip displacement was very small. Therefore, cumulative damage concept is necessary for the fuel rod wear. The mechanism of plowing is thought required to explain the severe wear in the case of gap existence.