고속철도차량 갱웨이 벨로우즈의 비선형 해석

강길현(Kang, Gil-Hyun),김철수(Kim, Chul-Soo) 한국산학기술학회 2013 한국산학기술학회논문지 Vol.14 No.8

갱웨이 벨로우즈는 관절형 고속철도차량 객차 끝단부 사이에 다양한 변위차를 고려하여 갱웨이 프레임에 장 착된 이중 주름구조 네오프렌 고무부품이다. 실제 운행중의 벨로우즈의 파손은 터널 통과시 기밀 파손으로 인한 이명 현상 발생과 함께 소음 증가로 승객의 승차감에 심각한 영향을 미친다. 본 연구에서는 고속철도차량 갱웨이 벨로우즈 의 안전성 연구일환으로서, 차량주행시 차량 끝단부의 3축 회전변위(롤링, 요잉, 피칭변위차)를 고려한 갱웨이 벨로우 즈의 비선형 해석을 수행하였다. 본 고무의 비선형 재료 특성은 단축인장 및 등2축 인장시험을 수행하여 구하였다. 또한, 비선형 해석결과로부터 회전변위 및 마찰계수의 영향을 평가하였다. Gangway bellows in this study is the double wrinkled neoprene rubber component to accept various deviations between the carriage end parts of the articulated type high speed railway vehicle(HSRV). The fatigue failure of the bellows has a harmful effect on the riding comfort for the passengers with the increase of noise and ringing in the ears due to air-tightness failure during pass through a long tunnel. In this study, to assure the safety of gangway bellows of the HSRV, non-linear analysis of the gangway bellows considering triaxial angular displacement(rolling /yawing/pitching) between the carriage end parts are performed. The non-linear properties of the rubber are determined by uniaxial tension and equi-biaxial tension test. Moreover, from the results of non-linear analysis, the effects of the angular displacements and frictional coefficients are evaluated.

철도차량용 패널 감쇠처리재의 감쇠계수 평가

강길현(Gil-Hyun Kang) 한국산학기술학회 2019 한국산학기술학회논문지 Vol.20 No.4

본 논문은 철도차량 및 자동차용 패널의 진동 및 소음억제용으로 사용되는 감쇠 처리재의 감쇠특성 평가에 관한 연구이다. 감쇠재의 모드별 매개변수들을 구하기 위해 다른 종류의 PVC를 알루미늄과 철계 빔위에 도포한 시편을 제작하여 가진시험을 수행하였다. 시편은 10 Hz부터 1,000 Hz까지의 주파수 대역을 조화력으로 가진하여 가속도계로 전달 모빌리티값을 측정하였다. 감쇠계수는 몇 가지 이론인 반력법, 최소 탄젠트오차법 및 최소 각오차법 조합법과 위상변화법을 모드 원호곡선 맞춤과 최소자승오차법을 사용하여 작성한 통합 프로그램을 이용하여 평가하였다. 감쇠값이 비교적 낮고 측정값이 선형인 경우는 어느 방법을 사용해도 되나, 감쇠값이 높거나 측정값에 비선형특성이 있는 경우에는 최소 각오차법이 감쇠계수 측정오차를 줄일 수 있다. 도포 감쇠재의 동적특성 평가로부터 구한 재료의 물성값은 차체나 철도차량 하부 기기함과 같이 복잡한 구조물의 소음해석을 위한 유한요소법에 사용할 수 있다. 빔 시험에서 수행한 모드별 감쇠계수의 특성 평가 결과 2차 이상 모드의 주파수 대역에서 감쇠 효과가 크기 때문에 구조소음억제에 유용할 것으로 사료된다. This paper is a study on the evaluation of loss factor of damping treatment materials to reduce the noise and vibration for panels of railway vehicles and automobiles. In order to determine the modal parameters of damping materials, beam excitation tests were carried out using different type PVC coated aluminum and steel base beam specimens. The specimens were excited from 10 Hz to 1000 Hz frequency range using sinusoidal force, and transfer mobility data were measured by using an accelerometer. The loss factors were determined by using integrated program, based on theories of Half Power Method, Minimum Tangent Error Method, Minimum Angle Error Method and Phase Change Method, which enable to evaluate the parameters using modal circle fit and least squares error method. In the case of lower loss factor and data of linear characteristics, any method could be applied for evaluation of parameters, however the case of higher loss factor or data including non-linear characteristics, the minimum angle error method could reduce the loss factor evaluation. The obtained dynamic properties of the coating material could be used for application of Finite Element Method analyzing the noise control effects of complex structures such as carbody or under-floor boxes of rolling stock. The damping material will be very useful to control the structural noise, because the obtained modal loss factors of each mode show very good effect on over 2<SUP>nd</SUP> mode frequency range.

철도차량 차체용 더블 스킨 알루미늄 압출 패널의 감쇠특성

강길현(Kang, Gil-Hyun),김철수(Kim, Chul-Soo) 한국산학기술학회 2013 한국산학기술학회논문지 Vol.14 No.7

철도차량 차체 설계시 음압레벨에 따른 소음해석을 통한 차체 패널의 감쇠특성을 최적화하는 것이 필요하다. 본 논문은 철도차량 차체용 알루미늄 더블스킨 압출패널의 진동감쇠특성 해석을 통한 철도차량 차체의 구조소음 해 석에 관한 연구이다. 주파수응답 가진시험을 통하여 측정된 기계적 모빌리티 값인 포인트 모빌리티, 트랜스퍼 모빌리 티, 모달 모빌리티와 단순음원이론을 사용하여 정규화된 음압을 계산하였다. 도포용 감쇠재의 감쇠값을 라미네이티드 쉘요소에 사용하여 유한요소해석을 수행함으로써, 감쇠처리에 의한 소음감소수준 예측을 하였다. 또한 실제 차량 구 조와 유사한 고정경계조건의 감쇠특성해석을 통하여 열차주행시 발생하는 진동의 영향을 크게 받는 언더프레임과 같 은 부위에 일정 두께의 감쇠재 코팅이 진동 및 소음억제에 큰 효과가 있을 것으로 사료된다. When car builder designs the large carbody structure of railway vehicles, it is necessary to optimize the damping characteristics through the analysis of structure borne noise such as sound pressure leve(SPL).This paper is a study on the structure borne noise analysis by characterizing the damping of double skin aluminum extruded panels for rolling stock carbody. The normalized SPL was calculated based on the simple source theory using measured mechanical mobility parameters from vibration tests(i.e. point, transfer and modal mobility). The reduced SPL was predicted by using finite element method by applying loss factor of damping material into laminated shell elements. It was found out that the damping material coated on the panels like underframe, which part is seriously affected by vibration during train run, took effect to reduce noise level.

사회복지 전공학생들의 공직동기 요인에 관한 연구

강길현(Kang Gil-Hyun) 한국지역사회학회 2017 지역사회연구 Vol.25 No.2

The study was intended to research social welfare major education, which has been frequently mentioned for the Public Service Motivation(PSM) granted to social welfare majors, the professional identity and volunteering experience have influenced, to analyze whether these factors can be different depending on the occupational values. To achieve the goal of study, we targeted 238 senior students of university in Jeon-nam, Jeon-buk and Gwangju. Following are the result of analysis. It showed the result of little more than name 36.1% among senior students, and finally selected non-major areas. Also the major subjects (theoretical understanding) in social welfare education didn’t influence the public service motivation. On the contrary, the professional job identity showed that the systematic knowledge, ethical conduct, professional culture and the volunteering experience have influenced to the public service motivation respectively. It was followed by the occupational values of control variations that have the control effects between the volunteer activity and the sympathy of public service motivation. But other variations did not show meaningful relations with the public service motivation and its control role. In order to have public service motivation by elevating the satisfaction level of social welfare major education, the contents of major subject should be improved while the expansion of volunteer activity, teacher’s training course, operation rule. Also guideline should be reviewed in order to elevate the public service motivation by enhancing the right occupational values. Therefore we suggest the measures which can elevate the public service motivation of students.

고속철도차량 관절대차 갱웨이 링의 내구성 평가

강길현(Gil-Hyun Kang) 한국산학기술학회 2019 한국산학기술학회논문지 Vol.20 No.5

동력 집중식 고속 철도차량의 승차감과 주행 안정성 향상 방안으로서 채택한 관절형 대차는 차체와 결합된 기존 독립대차와 달리 객차 사이를 갱웨이 링에 의하여 연결한다. 갱웨이 링은 열차 주행 동안 객차분리를 방지하면서 객차 사이 승객 이동에 대한 절대적 안전을 확보되어야 함에도 불구하고, 아직까지 정량적인 내구성 시험기준 설정이 미비하다. 따라서 동력 집중식 고속 철도차량의 승차감과 승객 안전성을 향상을 위해서는 관절형 대차 갱웨이 링에 대한 내구성 평가의 시험기준에 대한 체계적인 연구가 중요하다. 본 연구에서는 고속 철도차량 관절형 대차의 갱웨이 링에 대한 안전성을 검토하기 위하여, 열차 운행조건에 준한 전후, 좌우 및 수직의 3축 모드로부터 7가지 혼합모드 하중조건을 도출하였다. 이 하중조건하에 유한요소해석결과로부터 각 부품들의 안전율은 최소 2.4 이상이다. 또한 변형률-피로수명설계 관점에서 내구성 해석을 통하여 피로안전성을 평가하였다. 본 갱웨이 링에 대한 내구성 시험은 혼합모드 하중조건하에 총 4단계의 1,000만 사이클을 수행하였다. 내구성 시험 후에 침투 탐상 검사기법을 이용하여 각 부품의 결함유무를 검토하였다. To improve ride quality and running stability of high speed train(HST), it is important that connection between coaches adopts the articulated bogies by using a gangway ring, unlike the conventional independent bogies assembled with car bodies. Although the gangway ring should be ensured absolute safety against passenger movement between coaches during train operation, there is still a lack of quantitative durability criteria of that. Therefore, in order to improve the passenger safety of HST, it is important to study the test requirements on durability evaluation for the ring. In this study, seven mixed loading cases were derived from the triaxial loading(vertical/lateral/longitudinal) modes. The safety factor of each component is at least 2.4 or more from the results of the finite element analysis. In addition, fatigue safety was evaluated through durability analysis from the viewpoint of strain-life design. Durability tests for the gangway ring carried out a total of 10 million cycles in 4 phases load conditions. After the durability test, the defect of each component was investigated using nondestructive testing techniques.

고속철도차량 갱웨이 통로연결막의 내구성 평가

강길현(Kang, Gil-Hyun),우창수(Woo, Chang-Su),김철수(Kim, Chul-Soo) 한국산학기술학회 2014 한국산학기술학회논문지 Vol.15 No.8

관절형 고속철도차량의 승차감 향상 및 주행안전을 위해서는 객차 갱웨이 통로연결막에 대한 화재안전성, 방음기능 과 함께 3축 회전각변위(롤링/요잉/피칭) 모드하의 내구성을 만족하는 것이 중요하다. 그러나 국내의 경우 본 통로연결막에 대한 내구성 시험 및 규격은 아직 표준화되지 않고 있다. 본 연구에서는 비선형 구조해석 결과와 고무피로특성으로부터 피로 수명을 예측하였다. 또한, 리그 피로시험을 구축하여 본 부품의 내구성을 검토하였다. To increase the riding comfort and running stability of articulated type high speed railway vehicles(HSRV), it is important that the gangway connections for the passenger car satisfied fire safety, sound proof and durability under triaxial angular displacement (rolling/yawing/pitching) modes. On the other hand, a domestic test standard on the durability of the rubber components has not been determined. In this study, the fatigue life was predicted using the results of the nonlinear finite element analysis and the fatigue properties. Moreover, a fatigue rig test of the component was constructed to examine the durability.

한국고속철도차량(KTX)의 보수품 공급과 품질관리대책

강길현(Kang Gil-hyun) 한국철도학회 2005 한국철도학회 세미나자료 Vol.- No.-

In this paper, the supply and quality management counterplans for the KTX spare parts are studied for the soft landing after Apr. 2006 when the EUKORAIL engineers left the depots in KORAIL due to the expiration of the core contract term. The various investigations of the present supply, budget and investigation systems relating to the KTX operation and maintenance, then the future counterplans focusing on the improvement of supply and quality management system for the KORAIL. The supplement of experts on the field of spare parts as well as new regular cooperation among manufacturers, academic institutions and KORAIL are suggested.

직무 및 조직특성이 사회복지사의 이직의도에 미치는 영향

강길현(Kang-Gil Hyun),손재홍(Son-Jae Hong) 한국컴퓨터정보학회 2012 韓國컴퓨터情報學會論文誌 Vol.17 No.9

본 연구는 사회복지사들의 이직의도에 영향을 미치는 요인을 검증하는데 목적이 있다. 이를 위해 구조방정식모형(AMOS 16.0)을 통해 사회복지사의 이직의도에 미치는 영향요인에 대한 인과관계를 설정하여 직무특성과 조직특성이 이직의도에 직접적인 영향이 미치는지 또는 조직몰입을 매개로 하여 간접적으로 영향이 미치는지 살펴보았다. 연구 목적을 달성하기 위해 수도권을 포함한 시 도에서 민간 사회복지 관련 기관에 근무하는 사회복지사를 대상으로 설문조사를 실시하였다. 배포된 설문지 총 297부 중 이직의도가 확인된 설문지 256부를 최종 분석하였다. 분석결과 직무특성인 직무자율성과 조직특성인 승진절차공정성은 조직몰입에 영향을 미치는 것으로 나타났고, 직무요구성과 직무불안정, 임금수준은 이직의도에 영향을 미치는 것으로 나타났으며, 조직몰입은 이직의도에 영향을 미치는 것으로 나타났다. 이러한 연구결과를 통해 사회복지사들의 이직의도를 낮추기 위해서는 임파워먼트와 사회복지업무의 시스템화, 인적관리의 체계화, 의사소통의 활성화가 고려되어야 함을 알 수 있다. The purpose of this study is to investigate what affect social welfare workers' want of career change. The structural equation modeling(AMOS 16.0) was used to examine if job characteristics and organizational characteristics have direct affect on turnover intention or the indirect affect of organizational commitment. A survey was conducted on the social welfare workers of private social agencies in the capital area and 256 of 297 questionnaires that showed clear intentions on turnover were scrutinized. According to the analysis, job autonomy(job characteristics) and fairness in promotion (organization characteristics) influences organizational commitment. Job demand, job instability, wage level, and organizational commitment have and effect on turnover intention. The results of this study suggest that in order to reduce the turnover intention among social welfare workers, empowerment, systematic organization of tasks and active communication should be reinforced.

공격 시 돌려차기와 받아차기 시 돌려차기 동작에 관한 주동근 비교 분석

강길현(Kang, Gil-Hyun) 한국체육과학회 2014 한국체육과학회지 Vol.23 No.3

The purpose of this study was to investigate the differences in the agonist muscle activity during competition Dollyochagi and badachagi by recording the EMG aactivity of different phases. 1. There was no statistical difference in the average EMG value for the abdominal muscles during all phases. 2. There was no statistical difference in the average EMG value for the erector spinae during all phases. 3. There was no statistical difference at P1 but there was no statistical difference during P2 and P3 for average EMG for the biceps femoris. 4. There was no statistical difference in the average EMG value of the anterior tibialis during all phases. 5. There was no statistical difference in the average EMG value of the gastrocnemius during all phases. To summarize from the above results, there was a similar muscle pattern during the competition dollyochagi and the badachagi and for a powerful and accurate impact during the dollyochagi, as the foot leaves the floor there is a low level of muscle activity, and until the maximum knee flexion, the abdomium and quadriceps muscles coordination are important. At impact, for balance the errector spinae supports the back and is needed to maintain the posture of flexion for the upper body.

노인복지시설 종사자의 임금수준 적절성이 이직의도에 미치는 영향

강길현(Kang Gil-Hyun) 한국지역사회학회 2016 지역사회연구 Vol.24 No.4

This study analyzed the mediation role of exhaustion and the control effect of Servant Leadership from the effect that adequacy of wage of elderly welfare facilities practitioners influence the exhaustion and turnover intention. For this purpose, the survey was performed targeting 220 elderly welfare facilities practitioners in Gwangju, Jeonam and Jeonbuk after establishing research hypotheses and causality model through literature research. SPSS 22.0 statistical program was used and analyzed for the verification of measuring tool. The result of analysis showed that the adequacy of wages had the meaningful effect on the turnover intention and the depersonalization of exhaustion negatively. Also it showed that the depersonalization of exhaustion also had the mediating effect between the adequacy of wage and turnover intention. Depersonalization refers to“workers become indifferent to clients as they get emotionally drained.”In other words, it was judged that they had no consideration for clients as they had the turnover intention because of low wages. And it was researched that Servant Leadership didn’t play the role of control between the exhaustion and the adequacy of wage or between the adequacy of wage and turnover intention. To explain this, it was considered that Servant Leadership couldn’t play the role of control as the wage was directly related to living. But it was proved that it played the role of control between the exhaustion and turnover intention. It means that the role of superior can enhance the trust of subordinate to control the turnover intention. Therefore this study suggested the countermeasure which can improve the treatment of elderly welfare facilities practitioners based on such an analyzed result.