http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
혼합모드(I+II)에서 피로 하중에 의한 균열진전 거동
공병채(B.C. Gong),최성대(S.D. Choi) 한국생산제조학회 2012 한국생산제조학회지 Vol.21 No.2
This study looked for Mode status of each for fatigue crack growth behavior about the repeat load of mode I and the static load of mode Ⅱ. The experiment was performed in the state of the repetition frequency of the sine wave 10㎐, the stress ratio 0.1, maximum load 300㎏.f, a static load 0, 100, 200, 300㎏.f, As the experimental results, in mode of static load, while the load value increases, the crack growth rate is slower as the energy of a crack mixing grows. Mode Ⅰ and the power mode Ⅱ get an influence each other in the direction of crack propagation path, but as they eventually get closer to the breaking point of the crack growth, it is dominated by the mode I.
세대 난방온도조절기 유량 밸런싱 개선을 통한 운전성능 향상 방안 연구
공병채(Byeongchae Gong),안준성(Joonsung Ahn),황지현(Jihyun Hwang),이태원(Taewon Lee) 대한설비공학회 2022 대한설비공학회 학술발표대회논문집 Vol.2022 No.11
District heating, which is used in many apartment houses, has the advantage of reducing energy and decreasing air pollutants compared to individual heating. However, due to the flow rate deviation of the heating system of the users facility, the heating efficiency on the users side is deteriorating and the circulation pump power is wasted. This flow deviation is caused by the inability to control the differential pressure in the case of the system applied to the household. In order to improve this, the heating temperature controller used in household is replaced with a minimum flow rate linear control combined valve(DPV) to achieve flow balancing of the heating system. The replaced DPV achieves flow balancing by controlling the flow rate through proportional control. And improved flow balancing controls the same amount of heat at the minimum flow rate. This improves the temperature difference of the supply return water and reduces the pump power, resulting in a carbon neutral effect by reducing the pump power and electric energy.
혼합모드(Ⅰ+Ⅱ)에서 피로균열진전에 미치는 응력비의 영향
공병채(Byeong-Chae Gong),최명수(Myoung-Su Choi),권현규(Hyun-Kyu Kwon),최성대(Seong-Dae Choi) 한국기계가공학회 2009 한국기계가공학회지 Vol.8 No.4
The loading condition of actual construction works is complex. The shear effect of mixed-mode load component are crack propagation mechanism in step larger than the crack initial mechanism. Therefore, in this study received a mixed-mode loading on fatigue crack stress ratio on crack propagation path and speed of progress to leam whether stress affects crack propagation. ? P a constant state of fatigue tests in Mode I, II give the same stress ratio, frequency 10㎐, sinusoidal waveform was used. A lower stress ratio fatigue crack propagation angle is small. This is less affected by the Mode II. Therefore, a mixed-mode fatigue crack propagation is to progress by the Mode. Stress ratio in a mixed mode crack in the path of progress and found a lot of impact.
양세영,최성대,김기만,전재목,공병채,Yang, Se-Young,Choi, Seong-Dae,Kim, Gi-Man,Jun, Jea-Mok,Gong, Byeong-Chae 한국생산제조학회 2010 한국생산제조학회지 Vol.26 No.2
The general way to process the surface by means of the laser was heat treatment for strengthening the surface hardness. They have used the laser for changing the property of the surface, especially for metal. Generally, it is recent increasing tendency to use the thin plate panel for making things smaller and lightweight. However, thin plate should be strengthened or let the thin plate panel have moment of inertia by means of engraving the groove or wave on them for lightweight and strengthening. Therefore it is expected that the thin plate panel can be harder and more stable through processing the metal surface by laser beam irradiation and the hardness of thin plate possibly can be also changed how many parts of them are harden. Through this research, it can be grasped how the hardness and mechanical characteristic changes according to width and depth of groove by laser affect the max stress by the ratio of $A_H/A_T$ (hardening area/total area) and characteristic of displacement and structural characteristic for making the thin plate harder by the strengthening metal surface of thin plate by laser through the experiment and analysis of FEA can be presented.
홍종필(Jong-Pil Hong),공병채(Byeong-Chae Gong),최성대(Sung-Dae Choi),최현진(Hyun-Jin Choi),이달식(Dal-Sik Lee) 한국기계가공학회 2011 한국기계가공학회지 Vol.10 No.5
This study covers the optimum design of the 5-axis machine tool. In addition, the intelligent control secures structural stability through the optimum design of the structure of the 5-axis machine center, main spindle, and the tilting index table. The big requirement, like above, ultimately leads to speed-up operation. And this is inevitable to understand the vibration phenomenon and its related mechanical phenomenon in terms of productivity and its accuracy. In general, the productivity is correlated with the operation speed and it has become bigger by its vibration scale and the operation speed so far. Vibration phenomenon and its heat-transformation of the machine is naturally occurred during the operation. If these entire machinery phenomenons are interpreted through the constructive understanding and the interpretation of the naturally produced vibration and heat-transformation, it would be very useful to improve the rapidity and its stability of the machine operation indeed. In this dissertation, the problems of structure through heating, stability, dynamic aspect and safety about intelligent 5-wheel machine tool are discovered to examine. All these discoveries are applied to the structure in order to enhance the density of it. It aims to improve the stability.