• 대한건축학회논문집:구조계
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• 제36권4호
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• pp.135-142
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• 2020

The new method for evaluating the displacement tolerance of sky-bridges with pin-roller type supports was proposed considering both return period of phase difference between connected buildings and geometrical characteristics of skybridge. Because displacement tolerance is relative value, which is most affected by the phase difference of the connected buildings, the dynamic response of these building with time history analysis should be evaluated. However, the initial phase could not be specified, so the result of displacement tolerance would be varied with respect to initial value. Thus, the tolerance can be reasonably evaluated SRSS calculation with design displacements based on statistical approach and of each building. In addition, the geometrical characteristics of sky-bridge should be considered because the transverse displacement of sky-bridge span causes the shear deformation of the bridge and longitudinal displacement tolerance cannot release the shear deformation. Therefore, the some pin-end support in sky-bridge should have longitudinal displacement tolerance to accommodate the shear deformation. By resolving this shear deformation, it is possible not only to accommodate transverse displacement, but also to avoid the complicated joint details such as both pot bearing and guided supports with shear key.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.995-999
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• 1995

In spindle-bearing system, the displacement characteristics of the bearing by the load applied on the spindle are affected greatly by the assembling tolerance between the spindle and housing assembled to support the bearing. Also in spindle system of rotational operation, the compliance characteristic of the bearing is expected to be varied frequently by the thermal deformation of the spindle and the housing. To predict the thermal deformation of the spindle including heat generation of the bearing, we need to examine the effect on the compliance of spindle-bearing system by the assembling tolerance. In this paper, we proposed the load-displacement relation expression considering the effect which the variation of contact pressure due to the radial directional assembling tolerance between the bearing and the housing influences on the axial and radial directional displacement characteristics of the bearing. Furthermore, for several assembling systems of bearings and housings having all different assembling tolerances, we proposed a method to predict exactly the variation of the bearing preload which is sensitive to the thermal deformation by showing the propriety with experimental results.

• 한국측량학회지
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• 제30권4호
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• pp.363-368
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• 2012

선형 단순화 알고리듬의 결과물은 단순화 알고리듬의 선택, 임계값의 선택, 대상 객체의 선택 등에 의해 달라진다. 본 연구에서는 Sleeve-fitting, Visvalingam-Whyatt, Bend-simplify 알고리듬의 임계값을 5단계로 조절하여 건물, 하천, 도로 객체에 적용하고, 단순화 결과물에 대해 거리오차, 면적오차, 각오차를 측정하였다. 그리고 오차값들의 추세선을 통해 정성적인 분석을 실시하였다. 실험 결과 선형 단순화 알고리듬에서 임계값의 조절에 따른 오차값의 변화를 알 수 있었고, 선형 단순화 알고리듬들의 임계값의 변화에 따른 특징을 파악할 수 있었다.

• 풍력에너지저널
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• 제15권1호
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• pp.43-49
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• 2024

This study performed a response analysis according to the transmission error of the yaw drive. To perform the response analysis, the excitation source of the transmission error was modeled and the outer ring of the first stage bearing and the outer ring of the output shaft bearing were used as measurement positions. The response results were analyzed based on the vibration tolerance values of AGMA 6000-B96. As a result of the response of the first stage bearing outer ring, the maximum displacement of the first stage planetary gear system was 5.59 and the maximum displacement of the second to fourth stage planetary gear systems was 4.21 ㎛ , 3.13 ㎛ , and 25.6 ㎛ . In the case of the output shaft bearing outer ring, the maximum displacement of the first stage planetary gear system was 1.73 ㎛, and the maximum displacement of the second to fourth stage planetary gear system was 1.94 ㎛, 0.73 ㎛, and 2.03 ㎛. According to AGMA 6000-B96, the vibration tolerance of first stage is 17.5 ㎛, and the vibration tolerance of the second to fourth stages is 58 ㎛, 80 ㎛, and 375 ㎛, which shows that the vibration tolerance is satisfied and it is safe.

• 한국정밀공학회지
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• 제22권1호
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• pp.167-174
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• 2005

The design for cold extrusion dies is very important, because the die insert is subjected to very high radial and hoop stresses. The design of cold extrusion dies has many constrained conditions. In this paper, the used assumptions are such that the yield strength of each ring is selected according to the allowable tensile or compressive hoop stress in each ring and the maximum allowable inner pressure, when yielding occurs in one ring of the dies, is obtained by the proposed equation. In order to obtain design variables, such as diameter ratios and interferences, using the maximum inner pressure, the flexible tolerance method was used for shrink-fitted thick-walled cylinders. ANSYS APDL was used to perform the repeated analysis of deformation of the dies due to the variation of the design variables. The response surface methodology is utilized to analyze the relationship between the design variables and the maximum radial displacement of the die insert during extrusion. From the results, it is found that outer diameter of the die insert has the largest effect on the minimization of maximum radial displacement at the inner surface of the dies.

• 한국기계가공학회지
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• 제9권5호
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• pp.57-63
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• 2010

Tolerance analysis is one of the most important processes to improve the image quality of products. High resolution camera module for mobile phones needs precision assembly technology since the module becomes smaller and thinner. This paper will focus on the unit tolerance and the assembly tolerance which can affect the performance of the module. Lens shading and relative illumination were used to evaluate the optical axis scatter for each component on camera and estimate the assembly yield rate based on the evaluation result. A program was developed to analyze the impact on optical axis by each module, then to optimize the dimensions and tolerance for reducing the scatter of optical axis assembly. Through the simulation, though a rate of relative illumination was declined in where optical axis is displaced $100{\mu}m$ from sensor center, MTF performance is not influenced by increasing in optical axis displacement. It was seen that assembly yield was improved in result of simulation after correcting optical axis tolerance.

• 전산구조공학
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• 제11권1호
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• pp.161-170
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• 1998

길이가 긴 원통형 실린더를 구성하는 데에 사용될 조인트 부재에 대한 공차설계를 수행하였다. 즉, 원통형 실린더를 체결할 때 사용되는 조인트 부품 가운데 스터드 볼트를 최소 민감도해석에 의해 공차설계를 하였다. 조인트 부재의 공차설계를 위한 최소 민감도 해석에 의한 정식화는 목적함수가 폰 마이세스 응력의 공차에 대한 민감도이고, 여러 부등호 제약식 중에서 자중이 부등호 제안식에 포함된다. 조인트 부재의 경우 자중에 대한 타당한 부등호 제안식을 설정하기 위하여 우선 확정적인 경우에 대한 최적설계를 수행하여 그 범위값을 선정하였다. 원통형 부재의 구조 응답은 축대칭 유한요소로서 구조해석을 수행하여 제안식을 설정하였으며, 직접미분에 의해서 설계 민감도를 구하여 ,최적화 알고리즘과 결합하여 최적의 공차를 제시하였다.

• 한국정밀공학회지
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• 제15권3호
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• pp.24-30
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• 1998

Strength and displacement of jig body in index machine utilized for multiprocess machining such as drilling, boring and tapping, etc, at the same time were analyzed by the use of finite element analysis soft ware ANSYS 5.2A. The whole geometry was constructed by 4048 elements and 7016 nodes employing 8 node brick element. The analyses were carried out on five loading cases combining vertical and horizontal machining to simulate the case occurring large displacement and the one occurring small displacement one and provided following conclusions. (1) Jig body had sufficient strength because its safety factor was 6.95 even in the most severe loading case. (2) The largest displacement in Z direction was 549 m and that in radial direction was 43.7 m. (3) In order to reduce the displacement, vertical machining rather than horizontal or two or three processes should be adopted in the same station. (4) Alternate change of horizontal machining direction at consecutive stations can reduce the displace ment. (5) The dimension of the slider should be increased to reduce the displacement by the tolerance in the sliding part. (6) A bypass idle piston head needs to be installed to give a counterpart supporting load from opposite direction for a single horizontal machining case.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 제4회 압출 및 인발가공 심포지엄
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• pp.99-106
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• 2001

The design for cold extrusion dies is very important, because the die insert is subjected to very high radial and hoop stresses. The design of cold extrusion dies has many constrained conditions. In this paper, the used assumptions are such that the yield strength of each ring is selected according to the allowable tensile or compressive hoop stress in each ring and the maximum allowable inner pressure, when yielding occurs in one ring of the dies, is obtained by the proposed equation. In order to obtain design variables, such as diameter ratios and interferences, using the maximum inner pressure, the flexible tolerance method was used for shrink-fitted thick-walled cylinders. ANSYS APDL was used to perform the repeated analysis of deformation of the dies due to the variation of the design variables. The response surface methodology is utilized to analyze the relationship between the design variables and the maximum radial displacement of the die insert during extrusion. From the results, it is found that outer diameter of the die Insert has the largest effect on the minimization of maximum radial displacement at the inner surface of the dies.

• International Journal of Aeronautical and Space Sciences
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• 제13권2호
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• pp.221-228
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• 2012

An active compensation method for the deformation of composite structures using additional controllable metal parts is proposed, and its feasibility is experimentally investigated in a simulated space environment. Composite specimens are tested in a vacuum chamber, which is able to maintain pressure on the order of 10-3 torr and interior temperature in the range of ${\pm}30^{\circ}C$. The displacement-measuring interferometer system, which consists of a heterodyne HeNe laser and an interferometer, is used to measure the displacement of the whole structure. Meanwhile, the strain of the composite part and temperature of both parts are measured by fiber Bragg grating sensors and thermistors, respectively. The displacement of the composite structure is maintained within a tolerance of ${\pm}1{\mu}m$ by controlling the elongation of the metal part, which is bonded to the end of the composite part. Also, the possibility of fiber Bragg grating sensors as control input sensors is successfully demonstrated using a proper corrective factor based on the specimen temperature gradient data.