• 대한기계학회논문집
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• 제17권11호
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• pp.2704-2710
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• 1993

A simple and straightforward method is introduced for developing continuum beam-rod model of a box-beam typed aircraft wing with composite layered skin based on "energy equivalence." The equivalent continuum structral properties are obtained from the direct comparison of the reduced stiffness and mass matrices for box-beam typed wing with those for continuum beam-rod model. The stiffness and mass matrices are all represented in terms of the continuum degrees-of freedom defined in this paper. The finite-element method. The advantage of the present continuum method is to give every continuum structural properties including all possible coupling terms which represent the couplings between different deformations. To evaluate the continuum method developed in this paper, free vibration analyses for both continuum beam-rod and box-beam are conducted. Numerical tests show that the present continuum method gives very reliable structural and dynamic properties compared to the results by the conventional finite-element analysis. analysis.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.271-274
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• 2007

The finite element linear buckling analysis of folded plate structures using adaptive h-refinement methods is presented in this paper. The variable-node flat shell element used in this study possesses the drilling D.O.F. which, in addition to improvement of the element behavior, permits an easy connection to other elements with six degrees of freedom per node. The Box-typed structures can be analyzed using these developed flat shell elements. By introducing the variable node elements some difficulties associated with connecting the different layer patterns, which are common in the adaptive h-refinement on quadrilateral mesh, can be overcome. To obtain better stress field for the error estimation, the super-convergent patch recovery is used. The convergent buckling modes and the critical loads associated with these modes can be obtained.

• 대한기계학회논문집
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• 제19권3호
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• pp.615-622
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• 1995

It may be inefficient to conduct the aeroelastic analysis by using full-scale conventional finite-element analyses or experiments, from the initial design phase, for an aircraft wing which can be considered as the discontinuum complex structure with composite laminated skins. In this paper, therefore more efficient aeroelastic analysis has been conducted for a box-beam typed aircraft wing by using the equivalent continuum beam-rod model which is derived from the concept of energy equivalence. Equivalent structural properties of the continuum beam-rod model are obtained from the direct comparison of the finite-element matrices of continuum beam-rod model with those of box-beam typed aircraft wing. Numerical results by the continuum beam-rod model approach are compared with those by the conventional finite-element analysis approach to show that the continuum beam-rod model proposed herein is quite satisfactory as a simplified model of aircraft wing structure for aeroelastic analyses.

• 한국전산구조공학회논문집
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• 제20권3호
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• pp.265-272
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• 2007

본 논문에서는 적응적 h-유한요소 세분화에 의한 박스형 절판 구조물의 선형좌굴 유한요소해석법을 제안한다. 면내회전 자유도를 갖는 변절점 평판쉘유한요소를 사용하여 유한요소의 거동을 개선하고 6자유도를 갖는 다른 유한요소와의 자유도의 연결을 용이하게 한다. 이와 같이 개발된 평판쉘유한요소에 의하여 박스형 절판구조물의 정확한 구조해석이 가능한데, 변절점유한요소를 정식화함으로써 적응적 h-유한요소 세분화시에 발생하는 다른 패턴의 사각형 유한요소 세분화망의 연결을 용이하게 해결한다. 오차평가에 대한 개선된 응력장을 얻기 위하여 상위수렴 조각회복법을 적용한다. 이와 같이 상위수렴 조각회복법에 의한 개선된 응력장에 의하여 구성된 유한요소 세분화망을 이용하여 좌굴하중과 좌굴모드를 자동적으로 구할 수 있도록 한다.