• 복합신소재구조학회 논문집
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• 제1권2호
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• pp.59-65
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• 2010

단순지지된 슬래브교량의 경우 특별직교이방성 판이론에 의하여 해석하였다. 이 방법은 일반 기술자들에게는 너무 어려워서 현장에서 기술자들이 실무적으로 접근하기에는 많은 어려움이 있다. 본 연구에서는 일반 현장의 실무 기술자들이 사용할 수 있는 보 이론을 사용하여 단순지지된 콘크리트 슬래브를 단위 폭을 가진 보로 해석이 가능하도록 수정계수를 만들어서 실무에 적용할 때의 사용 가능한 자료를 만들고자 하였다. 본 연구에서는 1 : 1 ~ 1 : 6 까지 형상비를 변화 시켜가며 해석을 수행하였다. 본 논문의 연구의 결과는 단순지지된 슬래브교량의 해석에 이용할 수 있다.

• 산업기술연구
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• 제19권
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• pp.235-243
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• 1999

Vibration analysis for some of simple supported antisymmetric composite laminated plate loaded uniformly distributed axial force and attached mass was carried out. Because it is complicated to analysis this type of plate by theory of antisymmetric laminate, possibility for application of theory of special orthotropic laminate was studied, and natural frequency of laminated plate attached mass was calculated. Stiffness $B_{16}$, $B_{26}$, $D_{16}$, $D_{26}$ for this type of antisymmetric laminated plate converge on zero as the number of ply increases and it is possible to use classical theory by reason that considered plate has quasi-homogeneity without relevance to variation of angle. Difference between results by theory of antisymmetric and special orthotropic laminate is 0.36~1.96%, therefore it is convenient to analyze this by use of theory of special orthotropic laminate. When composite laminated plate with attached mass is analyzed range that was able to neglect self-weight of plate was proposed.

• 한국구조물진단유지관리공학회 논문집
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• 제4권4호
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• pp.181-190
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• 2000

Vibration analysis for some of simple supported antisymmetric composite laminated plate loaded uniform axial-loading and attached mass was carried out. Because it is complicated to analyze this type of plate by theory of antisymmetric laminate possibility for application of theory of special orthotropic laminate was studied, and natural frequency of laminated plate attached mass was calculated. Stiffness $B_{16}$, $B_{26}$, $D_{16}$, $D_{26}$ for this type of antisymmetric laminated plate converge on zero as the number of ply increases and it is possible to use classical theory by reason that considered plate has quasi-homogeneity without relevance to variation of angle. Difference between results by theory of antisymmetric and special orthotropic laminate is 0.36~1.96%, therefore it is convenient to analyze this by use of theory of special orthotropic laminate. When composite laminated plate with attached mass is analyzed range that Was able to neglect self-weight of plate was proposed.

• Steel and Composite Structures
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• 제21권6호
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• pp.1287-1306
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• 2016

The current research presents a buckling analysis of isotropic and orthotropic plates by proposing a new four variable refined plate theory. Contrary to the existing higher order shear deformation theories (HSDT) and the first shear deformation theory (FSDT), the proposed model uses a new displacement field which incorporates undetermined integral terms and involves only four variables. The governing equations for buckling analysis are deduced by utilizing the principle of virtual works. The analytical solution of a simply supported rectangular plate under the axial loading has been determined via the Navier method. Numerical investigations are performed by using the proposed model and the obtained results are compared with CPT solutions, FSDT solutions, and the existing exact solutions in the literature. It can be concluded that the developed four variable refined plate theory, which does not use shear correction coefficient, is not only simple but also comparable to the FSDT.

• Structural Engineering and Mechanics
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• 제65권4호
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• pp.491-504
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• 2018

Because of sandwich structures with low weight and high stiffness have much usage in various industries such as civil and aerospace engineering, in this article, buckling and free vibration analyses of coupled micro composite sandwich plates are investigated based on sinusoidal shear deformation (SSDT) and most general strain gradient theories (MGSGT). It is assumed that the sandwich structure rested on an orthotropic elastic foundation and make of four composite face sheets with temperature-dependent material properties that they reinforced by carbon and boron nitride nanotubes and two flexible transversely orthotropic cores. Mathematical formulation is presented using Hamilton's principle and governing equations of motions are derived based on energy approach and applying variation method for simply supported edges under electro-magneto-thermo-mechanical, axial buckling and pre-stresses loadings. In order to predict the effects of various parameters such as material length scale parameter, length to width ratio, length to thickness ratio, thickness of face sheets to core thickness ratio, nanotubes volume fraction, pre-stress load and orthotropic elastic medium on the natural frequencies and critical buckling load of double-bonded micro composite sandwich plates. It is found that orthotropic elastic medium has a special role on the system stability and increasing Winkler and Pasternak constants lead to enhance the natural frequency and critical buckling load of micro plates, while decrease natural frequency and critical buckling load with increasing temperature changes. Also, it is showed that pre-stresses due to help the axial buckling load causes that delay the buckling phenomenon. Moreover, it is concluded that the sandwich structures with orthotropic cores have high stiffness, but because they are not economical, thus it is necessary the sandwich plates reinforce by carbon or boron nitride nanotubes specially, because these nanotubes have important thermal and mechanical properties in comparison of the other reinforcement.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 추계학술발표대회 논문집
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• pp.171-174
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• 2003

The Special orthotropic plate theory is used for analysis of panels made of steel girders and cross-beams, and made of reinforced concrete. The cross-sections of girders and cross-beams are WF types. The result is compared with that of the beam theory. According to the numerical examination given in this paper, the result by the plate theory is 2.43 times stiffer than that of beam theory, The result for the concrete slab in given for the practicing engineers.

• 복합신소재구조학회 논문집
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• 제2권2호
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• pp.20-25
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• 2011

본 논문에서는 2차원 콘크리트 슬래브 철도교량을 특별직교이방성 복합적층판 이론으로 해석하였다. 슬래브의 해석에 있어 단면의 기하학적, 물리적 특성이 중립면에서 휨-연계강성 $B_{ij}$ = 0 이고, $D_{16}=D_{26}=0$임을 고려하였다. 교량상판은 특별직교이방성 판으로 거동한다. 이러한 경계조건을 갖는 단면 혹은 불규칙한 단면을 갖는 시스템은 해석적 해를 구하기가 매우 어렵다. 이러한 문제에 대한 해석을 위해서 유한차분법이 이용되었다. 본 논문에서는 보 이론과 유한차분법이 해석을 위해 사용되었다.

• Composites Research
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• 제22권5호
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• pp.24-29
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• 2009

본 논문에서는 포스트텐션된 철근콘크리트 슬래브를 특별직교이방성 복합적층판 이론으로 해석하였다. 슬래브의 해석에 있어 단면의 기하학적, 물리적 특성이 중립면에서 휨-연계강성 $B_{ij}=0$ 이고, $D_{16}=D_{26}=0$ 임을 고려하였다. 철근콘크리트 슬래브는 특별직교이방성판으로 거동한다. 이러한 경계조건을 갖는 단면 혹은 불규칙한 단면을 갖는 시스템은 해석적 해를 구하기가 매우 어렵다. 이러한 문제에 대한 해석을 위해서 유한차분법이 이용되었다. 본 논문에서는 유한차분법과 보 이론을 해석을 위해 사용되었다. 그 결과 보 이론에 의한 해석 값이 판 이론의 값에 근접함을 알 수 있었다.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
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• pp.258-264
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• 1999

In this study, a computer program was developed for analysis of the orthotropic curved ring sector plates. In the developing program , the thin-plate theory and multi-base coordinate system was adopted. The effect of design factors-boundary conditions, loading conditions, steel ratio, open angle, radius of curvature and relative flexural rigidity between slab and edge-beam-on the behavior of the circular ring sector plates were discussed. Also, the practical limitations was proposed to replace the problem of the orthotropic sector plate by equivalent rectangular plage.

• 대한기계학회논문집
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• 제13권4호
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• pp.595-603
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• 1989

본 연구에서는 양단이 단순지지되어 있는 특수 직교이방성 적층 복합재료 원추셸의 자유진동에 관한 지배방정식을 Flugge 이론으로부터 유도하고 Galerkin 방법을 적용하여 해를 구하였으며, 원추셸의 기하학적 매개변수 및 직교이방성 매개 변수의 변화에 따르는 진동특성을 고찰하였다.