유연 디스크 커플링의 비틀림 강성을 고려한 강성감소계수 산정

박형준,강효림,한승호 대한기계학회 2022 大韓機械學會論文集A Vol.46 No.11

Flexible disc couplings are used to smoothly transmit rotational powers between two shafts. Although the theoretical method proposed in the AGMA standard has been used to evaluate the torsional stiffness of couplings, it is challenging to accurately calculate the torsional stiffness owing to the out-of-plane deformation in the flexible disc pack. In this study, finite element models of two flexible disc couplings with different shapes, sizes, and torque capacities were established, in which the frictional conditions enabled the separation of contact surfaces for the flexible disc pack. The results of the finite element analysis showed that significant warping and out-of-plane deformation occurred in the flexible disc pack and increased the torsional angular displacement of the coupling. By comparing the torsional stiffness obtained from the theoretical and numerical results, the torsional stiffness reduction factors for the coupling were assessed and verified experimentally. 유연 디스크 커플링은 동력전달장치에서 오정렬을 허용하는 동시에 회전동력을 원활하게 전달하기 위해서 사용된다. 커플링의 비틀림 강성을 평가하기 위해서 AGMA 규격에서 제안한 이론식이 사용되고 있으나, 적층된 디스크 유연부재의 면외변형 거동으로 정확한 강성평가가 불가능하다. 본 연구에서는 형상, 크기 및 토크 용량이 서로 다른 두 유연 디스크 커플링을 대상으로, 적층된 얇은 디스크 간의 접촉 분리가 가능한 마찰조건을 구현하여 유한요소 모델을 구축하였다. 유한요소 해석 결과 비틀림 하중에 의해 압축 응력이 디스크 팩에 작용하면서 뒤틀림이 유발되고, 접촉면이 이탈되는 면외변형이 현저히 나타났다. 이는 여러 겹의 얇은 판으로 구성된 디스크 팩의 비틀림 각 변형에 큰 영향을 미쳐 제안된 커플링의 비틀림 강성을 현저하게 감소시켰다. 유한요소 해석을 통해 얻어진 결과를 이론식과 비교하여 디스크 유연부재에 의한 비틀림 강성감소계수를 산정하였고, 아울러 비틀림 시험을 수행하여 이의 정도를 평가하였다.

전단간섭계를 이용한 면외변형의 정량적 계측

장호섭(Ho-Seob Chang),정성욱(Sung-Wook Jung),김경석(Kyoung-Suk Kim),정현철(Hyun-Chul Jung) Korean Society for Precision Engineering 2007 한국정밀공학회지 Vol.24 No.4

Electronic Speckle Pattern Interferometry(ESPI) is a common method for measuring out-of-plane deformation and in-plane deformation and applied for vibration analysis and strain/stress analysis. However, ESPI is sensitive to environmental disturbance, which provide the limitation of industrial application. On the other hand, Shearography based on shearing interferometer which is insensitive to vibration disturbance can directly measure the first derivative of out-of-plane deformation. In this paper a technique that extract out-of-plane deformation from results of shearography by numerical processing is proposed and measurement results of ESPI and Shearoraphy are compared quantitatively.

ESPI를 이용한 자동차 TPS 면외변형 계측

한상길(Sang-Kil Han),함효식(Hyo-Shick Ham),함상현(Sang-Hyun Ham),이종황(Jong-Hwang Lee),정원욱(Won-Wook Jung),이창희(Chang-Hee Lee),이상봉(Sang-Bong Lee),최성을(Sung-Eul Choi) 한국비파괴검사학회 2010 한국비파괴검사학회지 Vol.30 No.5

본 논문에서는 ESPI 방법을 이용하여 자동차 엔진의 핵심 부품인 TPS의 열변형력에 따른 변외변형을 측정하여 열변형 특성을 분석하였다. 높은 해상도의 CCD와 줌렌즈를 사용하여 부품의 검사영역을 가로 세로 각각 5cm로 최소화하였다. 주행거리가 다른 TPS 부품들을 4-step 위상이동법과 위상 연속화를 통해 변형량이 연속적으로 변하는 위상도를 얻었고, 3차원으로 변형의 모양과 크기를 나타내었다. 약 70℃의 온도를 유지하면서 TPS 부품에 열을 가한 경우 주행거리가 길어질수록 TPS 변형은 크게 측정되었고, 위로 볼록한 형태로 변형되었다. 그리고 내부결함이 있는 부품에서는 위상도에 불연속적인 무늬가 나타났고, 아래로 오목한 모양을 갖는 변형으로 나타났다. In this paper, we analyzed the characteristics of thermal deformation of the TPS which is a core part of engine in vehicle by measuring out-of-plane deformation using ESP!. Inspection area of a test piece was minimized to 5 cm by 5 cm by using a high resolution CCD and a zoom lens. 4-step phase shifting method was used along with phase unwrapping algorithm to get a continuous phase map, configurations and deformations were displayed as 3D images. When heating the test pieces while maintaining the temperature at about 70℃, the out-of-plane deformations were measured. The results showed that a test piece with longer distance traveled tends to show larger thermal deformation, we could observes a convex shaped deformation on the surface. The inner defect sample, we could monitor discontinuous pattern phase map, and a concave shaped deformation on the surface.

면외변형이 구속된 강재이력댐퍼의 변형능력에 관한 실험적 연구

박해용 ( Park¸ Hae-yong ),김승훈 ( Kim¸ Seung-hun ),이용택 ( Lee¸ Yong-taeg ) 한국구조물진단유지관리공학회 2023 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.27 No.2

본 연구에서는 강재슬릿댐퍼를 대상으로 면외변형 구속을 위한 패널설치 유무에 따라 반복가력실험을 수행하였다. 구속패널의 설치효과는 강재슬릿댐퍼의 반복거동에서 발생할 수 있는 조기 면외변형을 억제함으로써 내력저하시점을 지연시키고 댐퍼파단 시까지 충분한 소성변형능력을 확보할 수 있음을 보였다. 이러한 구속패널효과는 댐퍼의 형상비와 가력진폭의 변화에 따라 차별적으로 나타났다. 누적소성변형 분석을 통해 댐퍼의 형상비와 가력진폭에 따른 구속패널 효과를 정량적으로 평가하였으며 제시한 결과는 향후 강재슬릿댐퍼의 실설계에 적절히 활용될 수 있을 것으로 기대된다.

레이저 계측을 이용한 곡관 감육부의 변형 해석

김경석(K. S. Kim),정현철(H. C. Jung),정성욱(S. W. Jung),곽재호(J. H. Kwag) 한국정밀공학회 2006 한국정밀공학회 학술발표대회 논문집 Vol.2006 No.5월

This study performs to investigate deformation of wall thinning pipe and to find out the position of the internal thinning defect by shearography. Shearography is one of optical methods those have applied to nondestructive testing (NDT) and the strain/stress analysis. This technique has the merit of the directly measuring the first derivative of displacement, sensitivity of which can be adjusted by the handling of optical component in interferometer. In this paper, we tested carbon steel pipe locally wall thinned and loaded internal pressure and developed the nondestructive out-of-plane deformation analysis technique for internal thinning defect of elbow by shearography. From the results, it was confirmed that this technique is proper to the practical application on the pipe line system with internal defect.

회전하는 얇은 링의 고유진동 해석을 위한 모델링

김창부(Kim, Chang-Boo),김세희(Kim, Sehee) 한국소음진동공학회 2006 한국소음진동공학회 논문집 Vol.16 No.1

In this paper, we present the principle of virtual work, from which the exact non-linear equations of motion of a rotating ring can be derived, by using the theory of finite deformation. For a thin ring of which the effect of variation in curvature across the cross-section is neglected, the radial displacement and the extensional stress are determined from the principle of virtual work at the steady state where the ring is rotating with a constant angular velocity. And also we formulate systematically the governing equations concerned to the in-plane vibrations and the out-of-plane vibrations at the disturbed state by using the principle of virtual work which is expressed with the disturbed displacements about the steady state. The formulated governing equations are classified by four models along the cases of considering or neglecting all or partly the secondary effects of flexural shear, rotary inertia, circumferential extension, and twist inertia. The natural vibrations of thin rings are analyzed, and its results are compared and discussed.

강판-대기 온도차에 의한 선체블록 주판의 부가 면외변형 추정

하윤석(Yunsok Ha),이명수(Myungsu Yi) 대한조선학회 2012 大韓造船學會 論文集 Vol.49 No.3

Study on the Out-of-Plane Deformation Measurement Condition through Comparison Photosensitivity

김현호(Hyun Ho Kim),강찬근(Chan Geun Kang),이현준(Hyun Jun Lee),정현철(Hyun Chul Jung),김경석(Kyeong Suk Kim),홍정기(Chung Ki Hong) Korean Society for Precision Engineering 2015 한국정밀공학회지 Vol.32 No.9

In the present study, an interferometer system, which integrates the laser sensitivity control technique based on the theory of electronic speckle pattern interferometry, one of non-contact non-destructive analysis methods, was developed. This interferometry system receives an image from CCD cameras for each reference and object, and compares the photosensitivity of the object and reference images from imagification. For the purpose of this study, the photosensitivity of object and reference light is measured with power meters, and the amount of light was controlled with an ND filter with a reference light port matching photosensitivity. Using the plate specimen as the object, 0.6, 0.9, 1.2, and 1.5 ㎛ of out-plane deformation was made, and images were compared according to the difference in photosensitivity. After analysis, larger object deformations showed larger numbers of stripe patterns. Images became clearer and data error was reduced when the photosensitivity of object and reference light matched.

전단간섭법을 이용한 배관 순환 시스템에서의 압력용기 내부결함 및 면외변형 측정

강찬근(Chan-Geun Kang),김현호(Hyun-Ho Kim),정현일(Hyun-Il Jung),최태호(Tae-Ho Choi),정현철(Hyun-Chul Jung),김경석(Kyeong-Suk Kim) 한국비파괴검사학회 2014 한국비파괴검사학회지 Vol.34 No.5

다양한 산업분야에서 사용되는 압력용기는 발전설비의 70~80%를 구성하는 설비구조물로써 유속에 의한 감육결함 현상이 발생할 수 있으며 내부결함 측정이 설비의 안전진단 평가에 중요한 요소가 된다. 본 논문에서는 광계측 응용 비파괴검사 기술인 전단간섭법을 이용하여 압력용기의 비접촉 비파괴평가를 통한 발전설비의 안정성 확보와 신뢰성 향상에 있다. 이를 검증하기 위하여 압력용기에 임의의 결함을 가공하여 배관 순환 시스템을 적용한 내부의 온도 변화와 압력 변화에 따른 내부결함 계측 및 면외 변형량 계측에 대하여 실험과 해석을 수행하였다. 본 연구를 통한 결함의 존재 유무를 구분할 수 있도록 하는 가장 중요한 요소는 결함 두께, 폭 및 결함길이라 할 수 있으며 결함 두께, 폭, 길이가 커질수록 변형랑도 커짐을 확인할 수 있었다. 따라서 전단간섭법을 이용한 압력용기의 내부결함을 사전에 측정하여 배관의 신뢰성과 건전성을 확보하는데 주요할 것으로 보인다. Wall thinning defects can occur in the pressure vessels used in a variety of industries. Such defects are related to the flow velocity. Considering the fact that such vessels constitute up to 70 or 80% of the plant structures in a power plant, it is important to measure internal defects as part of a safety evaluation. In this study, optical measurement were applied in a non-destructive evaluation using shearography to ensure the safety and improve the reliability of a power plant through the non-contact, non-destructive evaluation of pressure vessels. In order to verify whether the pressure vessels contained faults, experimental and analytical investigation were conducted to measure any internal defects and out-of-plane deformation from inner temperature changes and pressure changes in the piping of the circulation system. The most important factors in this research were the thickness, width, and length of a defect. An increase in these could confirm an increase in the deformation. Thus, internal defects in a pressure vessel were measured using shearography, which made it possible to ensure the reliability and integrity of the pipe.

벌크헤드 플레이트가 부착된 강바닥판교의 피로상세 개선 연구

공병승(BYUNG-SEUNG KONG) 한국해양공학회 2004 韓國海洋工學會誌 Vol.18 No.1

An orthotropic steel deck system is widely adapted form for a Iong-span bridge. It has many advantages, such as the big reduction of dead weight, the simplicity for erection, and the reduction of the construction period. However, an orthotropic steel deck system requires a lot of welding work, which may result in defects and deformation of connections. Therefore, the research for the general behavior and fatigue strength of the several details in orthotropic steel deck bridge is necessary. The fatigue failure with distortion results from secondary stress by out-of-plane deformation; these kinds of cracks are very difficult to measure, and can not be precisely calculated through finite element analysis. This stress concentration phenomenon generates the fatigue failure around the lower scallop of the transverse rib. This paper presents improved details of the intersection between the longitudinal rib and the transverse rib of an orthotropic steel deck bridge by the third dimensional full size test, and the finite element method, which can minimize local stress through parametric study.