• 한국컴퓨터정보학회논문지
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• 제12권5호
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• pp.285-292
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• 2007

본 논문은 정형외과영역인 대퇴부에 고정하여 사용하는 금속판으로 골 고정 골절치료의 유합술 골절치료를 할 수 있도록 구성하였는데, 사용되는 치료방법은 견고하고, 안정적이며, 역동적인 생물학적 금속판으로 고정 골수강 내 고정술을 적용되도록 견고한 골접촉 곡선형 시스템을 분석하였다. 금속판은 두 가지 유형으로 장형과 단형으로 구성되고, 금속판의 굴곡이 구조적이고 기하학적으로 경성 및 강도가 고루 분포하도록 최적화 하였다. 장 플레이트의 골접촉에 따른 곡선형으로 굽힙강도는 11,000N 이고, 단 플레이트의 골접촉에 따른 곡선형으로 굽힙강도는 6,525N 이며, 금속판에 골편간 압박을 주는 인장강도는 $1573N/m^2,\;1539N/m^2$정도이다. 금속판은 곡선부와 금속판부의 두 가지 부분으로 나뉘어져 있는데, 곡선부만 있는 단형과 밑 부분의 금속판이 달려있는 장형으로 진행되며, 곡선부의 단형은 전체적인 Profile이 낮고, 금속판이 달려있는 장형은 슬리브의 일체형으로 Profile보다 약간 높아져서 있다. 본 논문의 결과로 제공되는 것은 Hip Implant의 Revision case에 있어 보완뿐만 아니라 Hip Neck Fracture 경우에 사용되었던 Compression Hip Screw의 사용이 가능할 것으로 예상된다.

• Steel and Composite Structures
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• 제6권4호
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• pp.319-333
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• 2006

A rectangular plate made of a porous material is the subject of the work. Its mechanical properties vary continuously on the thickness of a plate. A mathematical model of this plate, which bases on nonlinear displacement functions taking into account shearing deformations, is presented. The assumed displacement field, linear geometrical and physical relationships permit to describe the total potential energy of a plate. Using the principle of stationarity of the total potential energy the set of five equilibrium equations for transversely and in-plane loaded plates is obtained. The derived equations are used for solving a problem of a bending simply supported plate loaded with transverse pressure. Moreover, the critical load of a bi-axially in-plane compressed plate is found. In both cases influence of parameters on obtained solutions such as a porosity coefficient or thickness ratio is analysed. In order to compare analytical results a finite element model of a porous plate is built using system ANSYS. Obtained numerical results are in agreement with analytical ones.

• 대한기계학회논문집A
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• 제31권8호
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• pp.896-902
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• 2007

The tunnel stability concerned with safety is very important in coal production process. The tunnel supports made by the GI beam has been used in domestic coal mine tunnels, and the GI beam was connected with another by the fish plate. It is necessary to analysis for the bending problems of the fish plate due to the rock pressure in some domestic mine tunnels. Therefore, this study proposes the application possibility of the optimization algorithms for the problem searching a load condition that bring about bending problem in tunnels. Consequently, in order to investigate the load conditions, desirability function as one of the optimization methods to study the bending behavior of tunnel supports was applied.

• International Journal of Naval Architecture and Ocean Engineering
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• 제7권5호
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• pp.805-816
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• 2015

In the present study, external restraints imposed normal to the plate during the cooling stage were determined to be effective for reduction of the angular distortion of butt-welded or fillet-welded plate. A welding analysis model under external force during the cooling stage was idealized as a prismatic member subjected to pure bending. The external restraint was represented by vertical force on both sides of the work piece and bending stress forms in the transverse direction. The additional bending stress distribution across the plate thickness was reflected in the improved inherent strain model, and a set of inherent strain charts with different levels of bending stress were newly calculated. From an elastic linear FE analysis using the inherent strain values taken from the chart and comparing them with those from a 3D thermal elasto-plastic FE analysis, welding deformation can be calculated.

• Structural Engineering and Mechanics
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• 제86권2호
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• pp.167-180
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• 2023

This work applies a four-known quasi-3D shear deformation theory to investigate the bending behavior of a functionally graded plate resting on a viscoelastic foundation and subjected to hygro-thermo-mechanical loading. The theory utilizes a hyperbolic shape function to predict the transverse shear stress, and the transverse stretching effect of the plate is considered. The principle of virtual displacement is applied to obtain the governing differential equations, and the Navier method, which comprises an exponential term, is used to obtain the solution. Novel to the current study, the impact of the viscoelastic foundation model, which includes a time-dependent viscosity parameter in addition to Winkler's and Pasternak parameters, is carefully investigated. Numerical examples are presented to validate the theory. A parametric study is conducted to study the effect of the damping coefficient, the linear and nonlinear loadings, the power-law index, and the plate width-tothickness ratio on the plate bending response. The results show that the presence of the viscoelastic foundation causes an 18% decrease in the plate deflection and about a 10% increase in transverse shear stresses under both linear and nonlinear loading conditions. Additionally, nonlinear loading causes a one-and-a-half times increase in horizontal stresses and a nearly two-times increase in normal transverse stresses compared to linear loading. Based on the article's findings, it can be concluded that the viscosity effect plays a significant role in the bending response of plates in hygrothermal environments. Hence it shall be considered in the design.

• 대한토목학회논문집
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• 제7권1호
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• pp.65-73
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• 1987

본(本) 연구(硏究)에서는 면내(面內) 고차(高次) 수평변위(水平變位)를 고려(考慮)한 6절점(節點) 21자유도(自由度)를 갖는 판(板) 유한요소(有限要素)를 Galerkin 가중잔차법(加重殘差法)으로 3차원(次元) 연속체(連續體)로부터 유도(誘導)하고 있다. 요소(要素)의 강성행렬(剛性行列)과 질량행렬(質量行列)은 판의(板) 운동방정식(運動方程式)을 이산화(離散化)(discretization)하여 ($3{\times}3$) Gauss 적분점(積分點)을 이용(利用)한 감차(減次) 적분(積分)을 수행(遂行)하여 구하였다. 본(本) 고차(高次) 판(板) 유한요소(有限要素)의 정확도(正確度)와 효율성(効率性)을 고찰(考察)하기 위하여 여러가지 경계조건(境界條件)을 갖는 정사각형(正四角形) 판(板)의 처짐해석(解析)을 수행(遂行)한 결과(結果), 판(板)의 두께에 관계없이 월등(越等)한 정확도(正確度)를 나타내었다.

• Structural Engineering and Mechanics
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• 제26권1호
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• pp.69-86
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• 2007

A four-noded plate bending quadrilateral (PBQ4) and an eight-noded plate bending quadrilateral (PBQ8) element based on Mindlin plate theory have been adopted for modeling the thick plates on elastic foundations using Winkler model. Transverse shear deformations have been included, and the stiffness matrices of the plate elements and the Winkler foundation stiffness matrices are developed using Finite Element Method based on thick plate theory. A computer program is coded for this purpose. Various loading and boundary conditions are considered, and examples from the literature are solved for comparison. Shear locking problem in the PBQ4 element is observed for small value of subgrade reaction and plate thickness. It is noted that prevention of shear locking problem in the analysis of the thin plate is generally possible by using element PBQ8. It can be concluded that, the element PBQ8 is more effective and reliable than element PBQ4 for solving problems of thin and thick plates on elastic foundations.

• 한국재난정보학회 논문집
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• 제17권4호
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• pp.839-847
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• 2021

연구목적: 본 연구에서는 휨을 받는 탄소 나노튜브 보강 기능경사복합재 판의 구조적 거동을 해석하였다. 이를 위해, 등기하해석과 고차전단변형이론을 결합한 수치해석 방법을 이용하였다. 연구방법: 전단보정계수를 사용하지 않고 기하학적 비선형성을 고려할 수 있는 고차전단변형이론을 통하여 휨이 작용하는 탄소 나노튜브 보강 기능경사복합재 판의 비선형 거동방정식을 유도하였으며, 수정된 Newton-Raphson 반복 기법을 사용하여 등기하해석방법에 기반한 시스템 방정식의 해를 구하였다. 연구결과: 탄소 나노튜브의 배치 양상, 폭-두께 비 및 경계조건은 휨을 받는 탄소 나노튜브 보강 기능경사복합재 판의 구조적 거동에 많은 영향을 끼침을 확인하였다. 결론: 제안된 고차전단변형이론에 근거한 등기하해석 방법은 휨을 받는 탄소 나노튜브 보강 기능경사복합재 판의 구조적 거동을 정확하고 효과적으로 해석하는 것을 알 수 있었다.

• Structural Engineering and Mechanics
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• 제6권7호
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• pp.727-746
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• 1998

Finite element models and numerical results are presented for bending and natural vibration using the unified third-order plate theory developed in Part 1 of this paper. The unified third-order theory contains the classical, first-order, and other third-order plate theories as special cases. Analytical solutions are developed using the Navier and L$\acute{e}$vy solution procedures (see Part 1 of the paper). Displacement finite element models of the unified third-order theory are developed herein. The finite element models are based on $C^0$ interpolation of the inplane displacements and rotation functions and $C^1$ interpolation of the transverse deflection. Numerical results of bending and natural vibration are presented to evaluate the accuracy of various plate theories.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1992년도 봄 학술발표회 논문집
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• pp.7-12
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• 1992

The variable node plate bending element, ie, the element with one or two additional mid-side nodes is used in the analysis of mat foundation to generate the nearly ideal grid model in which more nodes are defined near the column location. The plate bending element used in this study is the one based on Mindlin/Reissner plate theory with substitute shear strain field and the nodal stresses of that element are obtained by the local smoothing technique. The interaction of the soil material with the mat foundation is modeled with Winkler springs connected to the nodal points in the mat model. The vertical stiffness of the soil material are represented in terms of a modulus of subgrade reaction and are computed in the same way as to the computation of consistent nodal force of uniform surface loading. Several mesh schemes were proposed and tested to find the most suitable scheme for mat foundation analysis.