• Journal of the KSME
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• v.23 no.6
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• pp.448-458
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• 1983

보의 처짐(deflection of beam) 및 부정정보(statically indeterminate beam)의 문제는 수문이나 압력용기등을 비롯한 각종 구조물의 강도계산에서 설계자가 자주 부딪치는 문제이다. 일반적으로 분포하중이나 집중하중 또는 집중 모우멘트가 작용하는 보, 특히 부정정 보의 경우 해석하기 쉬운 방법을 찾아 모우멘트-면적법, 중첩법, 3-모우멘트의 방정식등을 사용하여 반력이나 반력 모우멘트, 처짐량 등을 계산하고 있다. 그러나 이들 방식들은 일률적으로 어느 경우에나 적용하기에 적합한 것은 아니고 복잡한 각종 정리나 공식들을 사용하여야 하며 공액보(conjugated beam)의 반력을 구한다든가, 선도의 면적을 구하기 위하여 힘든 계산을 행하여야 하는 등 쉽지 않아, 부정정 보를 풀어야 할 경우가 발생할 때마다 좀 더 쉬운 접근방법이 없을까 하는 애로를 느껴왔다. 그러던 차 특이함수를 도입하여 문제의 해결을 시도하여 본 바, 복잡한 공식들을 외울 필요 없이 규칙적이고 일률적인 방법으로 쉽게 문제의 해결이 가능하기에 여기 간단히 풀이 방법을 소개하고자 한다.

• Journal of Drive and Control
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• v.12 no.4
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• pp.35-40
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• 2015

A gas spring provides support force for lifting, positioning, lowering, and counterbalancing weights. It offers a wide range of reaction force with a flat force characteristic, simple mounting, compact size, speed controlled damping, and cushioned end motion. The most common usage is as a support on a horizontally hinged automotive tail gate. However, its versatility and ease of use has been applied in many other industrial applications ranging from office equipment to off-road vehicles. The cylinder of a gas spring is filled with compressed nitrogen gas, which is applied with equal pressure on both sides of the piston. The surface area of the rod side of the piston is smaller than the opposite side, producing a pushing force. The magnitude of the reaction force is determined by the cross-sectional area of the piston rod and the internal pressure inside the cylinder. The reaction force is influenced by many design parameters such as initial chamber volume, diameter ratio, etc. In this paper, we investigated the reaction force characteristics and carried out parameter sensitivity analysis for the design parameters of a gas spring.

• Journal of Drive and Control
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• v.12 no.4
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• pp.15-20
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• 2015

Unlike a typical metal spring, a gas spring uses compressed gas contained in a cylinder and compressed by a piston to exert a force. A common application includes automobiles where gas spring are incorporated into the design of open struts that support the weight of tail gate. They are also used in furniture such as office chairs, and in medical and aerospace applications. The gas spring works by the application of pressurized gas (nitrogen) contained in a cylinder. The internal pressure of the gas spring greatly exceeds atmospheric pressure. This differential in pressure exists at any rod position and generates an outward force on the rod, making the gas spring extend. In this paper, we investigated the dynamic characteristics of a gas spring on an automotive tail gate system.