모아레 간섭계를 이용한 CBGA 패키지의 비선형 열변형 해석

주진원(Jinwon Joo),한봉태(Bongtae Han),조승민(Seungmin Cho) 대한기계학회 2002 대한기계학회 춘추학술대회 Vol.2002 No.8

Thermo-mechanical behavior of a ceramic ball grid array (CBGA) package assembly are characterized by high sensitive moire interferometry. Moire fringe patterns are recorded and analyzed at various temperatures. Thermal-history dependent analyses of global and local deformations are presented. A significant non-linear global behavior is documented due to stress relaxation at high temperature. Analysis of the solder interconnections reveals that inelastic deformation accumulates at eutectic solder fillets only at high temperatures.

무아레 간섭계를 이용한 BGA 패키지의 열변형 해석모델 평가

주진원(Jinwon Joo),최용서(Yongseo Choi),Seungmin Cho,Bongtae Han 대한기계학회 2002 대한기계학회 기타 간행물 Vol.2002 No.11

극돌기 간 삽입체의 스파이크에 대한 하중시험 및 유한요소 해석

김경혜 ( Kyunghye Kim ),주진원 ( Jinwon Joo ) 충북대학교 산업과학기술연구소 2024 산업과학기술연구 논문집 Vol.38 No.1

The interspinous spacer (ISP) is a device that is inserted and fixed between the spinous processes at the back of the vertebral body to act as a cushion, enabling the distribution of loads on the spine and stabilization of the spine without performing a bone resection decompression surgery. This paper compares the strength of different models of interspinous spacers with varying lengths and shapes of spikes to enhance the mechanical strength and fixation of the spacer. To this end, mechanical property tests of interspinous spacers with different lengths were conducted to compare their strength. Additionally, finite element analysis was used to compare the mechanical test results and optimize the design to minimize failure of the interspinous spacer based on the shape of the spikes. The results of compression load tests with varying spike lengths of the interspinous spacers showed that the average yield load and ultimate load were higher for longer spikes compared to shorter spikes. Furthermore, the tensile and torsion test results showed values at least 1.8 times higher than the tensile yield load and torsion load specified by other certified products used clinically. Based on the results of the tensile and torsion tests, it was concluded that the interspinous spacer developed in this study can be reliably used in terms of strength.

휠 동력계의 성능향상을 위한 구조해석

박용욱(YongWook Park),주진원(JinWon Joo) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11

Wheel dynamometer measures load of wheel shaft during drive. We analyze structure of wheel dynamometer and proposes better design. Conventional design of Wheel dynamometer include four beam structure owing to decrease of interference error. However, it is unstable in variety of conditions. This paper put forward several shapes or beam type and form of slit, and study it. On the other side, interference errors were minimized by using wheatstone bridge circuit of data on the finite element analysis. Also we’ll use shear strain type gauges and draw graphs of strain contour on many forms of wheel dynamometer they are suitable.

LED 파장에 따른 모아레 무늬의 평가

유현창(Hyunchang Yoo),주진원(Jinwon Joo) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11

유한요소해석을 이용한 롤투롤 가이드 롤러 브래킷의 최적화 설계

노승완 ( Seungwan Noh ),주진원 ( Jinwon Joo ) 충북대학교 산업과학기술연구소 2023 산업과학기술연구 논문집 Vol.37 No.1

This paper focuses on the optimization design of the cantilever guide roller bracket for roll-to-roll systems using finite element analysis. Guide rollers play a crucial role in roll-to-roll manufacturing processes, ensuring stable material movement and accurate positioning. The optimal design configurations that maximize the strength and rigidity of the guide roller brackets while minimizing their weight. The results demonstrate significant improvements in structural performance, with a reduction of 23% in deflection compared to the initial aluminum material and a 66% reduction in weight compared to the initial steel material, meeting the stringent precision requirements of Class B for roll-to-roll systems. This research provides valuable insights into the optimization of cantilever guide roller bracket designs for roll-to-roll systems using finite element analysis. The optimized brackets contribute to improved stability, reduced deflection, and increased efficiency in roll-to-roll manufacturing processes, thereby offering significant potential for various industrial applications.

실버 패턴 스트레인 게이지의 특성시험 연구

정홍식(Hongsik Chung),주진원(Jinwon Joo) 대한기계학회 2012 대한기계학회 춘추학술대회 Vol.2012 No.11

A traditional capacitive touch panel use in-plane force as an input value. For sensing out-of-plane force, touch panel embedded strain gage has been tried using silver patterned printing technique. In this paper, characteristic test of embedded strain gages were performed for determination of gage factor. A robust steel cantilever beam is designed and used, where the width of the beam is tapered to produce a state of uniform strain along its top and bottom surfaces. Thin glass on which silver pattern is printed was bonded on this steel beam, and measurement of gage factor was carried out.

유한요소 해석과 그림자 모아레 방법을 이용한 쌍안경식 로드셀의 변형 해석

윤경선 ( Kyeongseon Yoon ),주진원 ( Jinwon Joo ) 충북대학교 산업과학기술연구소 2023 산업과학기술연구 논문집 Vol.37 No.1

The binocular load cell is widely used for measuring low-capacity loads due to its advantageous features such as a low profile, easy manufacturing process, and the ability to accurately measure strain at the location where the strain gauge is attached. This paper focuses on the design of the load cell's shape and dimensions using beam theory principles. The bending strain generated by the load cell was analyzed through theoretical, numerical, and experimental methods. Finite element analysis was conducted to evaluate the load cell's performance, and the results were compared to the assumptions made in the beam theory. Actual strain gauges were attached to measure and compare the strain, while displacement was analyzed using the shadow moire technique. The strain analysis results obtained through finite element analysis showed good agreement with the strain measurements from the strain gauges, with a difference of less than 5%. The displacement values measured using the shadow moire technique at the strain gauge location of the binocular load cell aligned well with both the strain analysis values obtained through finite element analysis and the strain measurements.

스트레인 게이지 휘스톤 브리지 회로 출력 측정 비교 연구

최윤희 ( Yunhui Choi ),주진원 ( Jinwon Joo ) 충북대학교 건설기술연구소 2019 建設技術論文集 Vol.38 No.1

스트레인 게이지로 휘스톤 브리지회로를 구성하고, 저항변화에 의해 변화된 휘스톤 브리지 회로의 전압변화율로부터 게이지 상수 값을 이용해 변형률을 결정한다. 브리지 회로를 구성하는 방법은 1/4 브리지(quarter bridge), 1/2 브리지(half bridge), 완전 결선 브리지(full bridge) 가 있다. 본 논문에서는 실험을 통해 1/4 브리지의 출력과 완전결선 브리지의 출력을 비교하였다. 또한 출력 변형률 대신에 출력한 전압을 직접 측정하여 단위변환을 진행한 후의 여러 브리지의 출력을 비교하였다. 완전결선 브리지와 1/4브리지를 이용한 변형률 측정 실험 결과, P3 인디케이터를 이용한 측정 시에는 0.9 μm/m의 차이가 발생하였고, MX440A 인디케이터를 이용한 측정 시에는 0.8 μm/m의 차이가 발생했으며, 이는 완전결선 브리지 결과에 대해 각0.09 %, 0.08 %로 매우 작은 오차가 발생하였다. 또한, 전압 측정 실험 결과 완전결선브리지와 1/4브리지의 결과 값 차이는 P3인디케이터를 이용한 측정 시 0.001 mV/V가 발생하였고, MX440A 인디케이터를 이용한 측정 시 0.013 mV/V의 차이가 발생하였으며, 이는 완전결선 브리지의 변형률 측정 결과에 대해 각 0.04 %, 0.6 %이다. MX440A 인디케이터를 이용한 측정 시 발생하는 차이의 원인을 분석하기 위해 추가 실험을 진행하였다. 추가 실험 결과 하중이 증가할수록 μm/m로 측정한 결과보다 mV/V로 측정한 후 환산한 값이 작게 나왔으며, 변형률에 대해 약 0.5 %의 차이를 보였다. A Wheatstone bridge circuit is constituted by a strain gauge and the strain is determined by using the gauge constant value from the voltage change rate of the Wheatstone bridge circuit changed by the resistance change. The method of constructing the bridge circuit is a quarter bridge, a half bridge, and a full bridge. In this paper, the output of the 1/4 bridge is compared with the output of the full bridge by experiments. In addition, the output voltage was directly measured instead of the output strain, and the outputs of the various bridges after the unit conversion were compared. As a result of the strain measurement using the full bridge and the 1/4 bridge, there was a difference of 0.9 μm/m in the measurement using the P3 indicator and 0.8 μm/m in the measurement using the MX440A indicator, 0.09 % and 0.08 %, respectively, for the complete bridge results. In addition, as a result of the voltage measurement experiment, the difference of the result of full bridge and 1/4 bridge was 0.001 mV/V when measured with P3 indicator and 0.013 mV/V when measured with MX440A indicator, 0.04 % and 0.6 %, respectively, for the strain measurement results of the fully connected bridge. Additional experiments were conducted to analyze the cause of differences in the measurement using the MX440A indicator. As a result of the additional test, the value converted to mV/V was smaller than that measured in μm/m as the load increased, and the difference was about 0.5 % with respect to the strain.

회전형 암을 가진 굴삭기의 응력해석 및 안전성 평가

최윤희 ( Yunhui Choi ),주진원 ( Jinwon Joo ) 충북대학교 건설기술연구소 2018 建設技術論文集 Vol.37 No.1

기존에 사용되었던 굴삭기에서 암 자체가 36° 회전이 가능하도록 교체하여 개발한 굴삭기의 안전성 평가를 위해서는 해석적, 실험적인 검증이 필요하다. 본 논문에서는 유한요소해석 프로그램인 Ansys workbench를 사용하여 개발을 위해 설계된 암을 포함한 굴삭기의 응력해석을 수행하고 안전성을 평가하였다. 회전형 암이 장착된 굴삭기 전체의 상당응력은 107.86 MPa로 계산되었고, 붐과 암 부분의 변위를 계산하여 변위 경계조건으로 부여한 암 자체의 모델에 대한 해석결과, 상당응력은 106.0 MPa로 계산되었다. 220 MPa의 허용응력을 고려할 때 충분히 안전한 설계가 이루어진 것을 확인하였으며, 개발된 굴삭기에 약 200%의 하중이 가해지더라도 강도에는 큰 문제가 없는 것으로 판단되었다. Analytical and experimental verification is required to evaluate the safety of the excavator developed by replacing the existing excavator so that the arm itself can rotate. In this paper, the stress analysis of an excavator including an arm designed for development using the Ansys workbench, which is a finite element analysis program, was performed and its safety was evaluated. The equivalent stress of the whole excavator equipped with a rotary arm was calculated to be 107.86 MPa, and the equivalent stress was calculated to be 106.0 MPa as a result of the analysis of the model of the arm itself given as the displacement boundary condition by calculating the displacement of the boom and arm part. Considering the allowable stress of 220 MPa, it is confirmed that the design is safe enough. Even if the developed excavator is loaded with about 200%, it is expected that there is no big problem in strength.