• 제어로봇시스템학회논문지
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• 제22권8호
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• pp.610-614
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• 2016

This paper proposes an inextensible wire-shaped deformation model to simulate catheter behavior. The wire-shaped model consists of serially-connected mass points and massless rigid links. Torsional springs and dampers are employed to accommodate bending. Deformation is computed by updating the rotation angles from the global coordinates while maintaining the fixed length condition. Equations of motion is derived from double pendulum motion. Spring constant is computed using strain energy and potential energy stored in a torsional spring to reflect material property. Simulation is conducted to show deformation of wire model while maintaining inextensibility condition and including material properties. The proposed method guarantees inextensible constraint in the catheter simulation.

• Computers and Concrete
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• 제17권1호
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• pp.1-27
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• 2016

Final construction project cost is significantly determined by construction rate. The Industrialized Building System (IBS) was promoted to enhance the importance of prefabrication technology rather than conventional methods in construction. Ensuring the stability of a building constructed by using IBS is a challenging issue. Accordingly, the connections in a prefabricated building have a basic, natural, and essential role in providing the best continuity among the members of the building. Deficiencies of conventional precast connections were observed when precast buildings experience a large induced load, such as earthquakes and other disasters. Thus, researchers aim to determine the behavior of precast concrete structure with a specific type of connection. To clarify this problem, this study investigates the capacity behavior of precast concrete panel connections for industrial buildings with a new type of precast wall-to-wall connection (i.e., U-shaped steel channel connection). This capacity behavior is compared with the capacity behavior of precast concrete panel connections for industrial buildings that used a common approach (i.e., loop connection), which is subjected to monotonic loading as in-plane and out-of-plane loading by developing a finite element model. The principal stress distribution, deformation of concrete panels and welded wire mesh (BRC) reinforcements, plastic strain trend in the concrete panels and connections, and crack propagations are investigated for the aforementioned connection. Pushover analysis revealed that loop connections have significant defects in terms of strength for in-plane and out-of-plane loads at three translational degrees of freedom compared with the U-shaped steel channel connection.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1643-1646
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• 2003

Drawing is a mechanical operation that attenuates thick material to an appropriate thickness for the next processing or end usage. When the input material has the form of a bundle or bundles made of very thin and long shaped wire or fibers, this attenuation operation is called "bundle drawing" or "drafting" Drafting is being used widely in manufacturing staple yarns. which is indispensable for the textile industry. However, the bundle processed by this operation undertake more or less defects in the evenness of linear density. Such irregularities cause many problems not only for the product quality but also for the efficiency of the next successive processes. Since long there have been many researches tying to find out factors affecting the irregularity of linear desity, to obtain optimal drafting conditions, to develop efficient measuring and analysis methods of linear density of bundle, etc., but there exists yet no fundamental equation describing the dynamic behavior of the flowing bundle during processing. In this research a mathematical model for the dynamic behavior of the bundle fluid is to be set up on the basis of general physical lows representing physical variables, i.e. linear density and velocity as the dynamic state of bundle. The conservation of mass and momentum balance was applied to the fluid field of bundle. while the movement of′ individual material was taken into account. The constitutive model relating the surface force and the deformation of bundle was introduced by considering a representative prodedure that stands for the bundle movement. Then a fundamental equations system could be simplified considering a steady state of the process. On the basis of the simplified model, the simulation was performed and the results could be confirmed by the experiments under various conditions.

• 수산해양기술연구
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• 제24권2호
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• pp.55-64
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• 1988

부산시 선적의 근해안강망 어선에서 사용하고 있는 어구의 1/10, 1/20 모형을 제작하여 흐름이 비교적 빠른 연안에서 전개상태를 측정 및 관찰한 결과는 다음과 같다. 1. 전개장치의 전개높이, 전개간극 등은 네갈랫줄의 상대적 길이에 따라 상당히 다르며, 보편적으로 사용하고 있는 바와 같이 네갈랫줄의 길이를 길게 하고, 맨 위쪽 줄의 길이를 그 보다는 짧게한 방식이 효과적이며, 가장 효과적인 것은 갈랫줄의 길이를 아래로부터 차례로 맨 아랫것 보다 5%, 9%, 4%씩 길게 한 것이 전개 높이, 전개간극, 전개면적 등의 모든 면에서 가장 효과적이었다. 2. 흐름이 빨라지면 등판과 밑판의 평면형상은 뜸줄과 발줄이 아주 심하게 만곡되고, 그물 길이의 2/5 정도까지는 망지가 뒤로 많이 쏠려서 망구에 있어서의 물의 여과를 혼란시켜 어군의 입망을 방해할 것 같고, 또 밑판이 해저의 장애물에 걸렸을 때는 파망의 우려가 크다. 3. 유체저항을 실물어구의 것으로 환산하면 R=29.2$\times$103 v1.65 이라고 표현되고, 이것을 그물의 설계상 구성요소를 고려한 식으로 바꾸면 R=5.9$\times$d/l$\times$abv1.65 이라고 표현된다.