본 연구에서는 DVR 내부 공기유동을 직접 제어하여 CPU의 온도를 낮추기 위한 유동제어 구조물을 제안하였다. 제안된 구조물은 세 개의 얇은 판의 형태로 구성되었으며, DVR 내부의 공기 유동을 포괄적으로 제어하여 CPU의 효율적인 방열을 유도하고자 하였다. DOE와 RSM을 이용한 매개변수 연구기법을 통해 유동제어 구조물의 형상을 최적화하였으며, 해석에는 유한체적방법을 이용한 유체역학 분석 패키지인 FlowVision을 사용하였다. 실제 DVR 기기에서의 실험을 통해 해석 결과를 검증한 결과 CPU의 온도가 16.1℃ 낮아짐을 확인하였다

This study investigated a bio-tensegrity structural system that combines the characteristics of a general tensegrity structural system with a biological system. The final research objective is to accomplish a changeability for the structural system as like the movement of the natural bio-system. In the study, we present a shape finding procedure for the two stage bio-tensegrity system model inspired by the movement pattern of animal backbone. The proposed system is allowing a dynamic movement by introducing the concept of “saddle” for the variable bio-tensegrity structure. Several shape finding analysis example and results are presented and shows a efficient validation and suitability.

In the present study, FE analysis was performed for characterising structural strength of a seat frame w.r.t. varying sectional shapes as well as different materials of the seat back frame based on the FMVSS 207 regulation in order to obtain the design outline of a lightweight seat frane structure. Four types of materials, i.e., SAPH440, Al7021, Al6082 and carbon/epoxy composites were applied to the seat back frame type beams and their bending behaviours were compared by three point bending FE analysis. Consequently, the lightweight structure of seat back frame with the equivalent strength characteristics of conventional frame was suggested.

건축구조기준(KBC-2016)에서는 팔각기둥 형상을 가진 구조물의 풍력계수는 형상비 25이상에서 1.4로 일정한 값을 적용하도록 하고 있다. 하지만 팔각뿔 형상인 첨탑 구조물은 팔각기둥과는 그 형상이 다르기 때문에 첨탑 구조물에 적용할 풍력계수에 관한 연구가 필요하다. 본 논문에서는 풍동실험을 이용하여 첨탑 구조물의 형상비 변화에 따른 풍력계수 특성을 규명하였다. 일반적으로 구조물에 작용하는 풍력계수는 형상비가 증가할수록 커진다. 하지만 특정 형상비를 초과하면 풍력계수는 더 이상 증가하지 않고 일정하게 수렴한다. 이러한 특성을 반영하기 위해, 예비실험은 형상비가 10~19.2인 모델에 대해 수행하였고, 풍력계수가 수렴하기 시작하는 형상비를 검토하였다. 그 결과 15 이상의 형상비에서 풍력계수가 약 1.1로 수렴하는 것으로 나타났다. 형상비 변화에 따른 풍력계수 변화를 고찰하기 위해 형상비 3~8.5 까지의 모형을 추가 제작하여 풍동실험을 수행하였다. 연구의 결과를 이용하여 형상비 변화에 따른 풍력계수의 변화를 경험식으로 제안하였고, 추세한 값들이 실험값 보다 작지 않도록 보정하였다.

In the present study, the structural and fatigue analysis on the shape change of an automatic press are investigated for prediction of operation safety and reliability of the automatic press along the thickness(t) and length(L) of head, and corner shapes(case 1, 2, 3). The equivalent stress and deformation characteristics of the automatic press were studied by computerized analysis method for the bushing production of the seat frame. An external stress of 14.0 MPa was applied to predict the operation stability and the fatigue limit of the structure. As the thickness of the header increased and the length of the header decreased, the load stability applied by the piston improved and the maximum stress and deformation were reduced. In addition, due to the change in shape of the corners, the load applied at the cross-sectional area of the corners decreases, and then the maximum stress and deformation appearing in the header are reduced. That is, the change of corner shapes affects the equivalent stress and deformation. That is the change of corner shapes affects the equivalent stress and deformation. From the fatigue and vibration analysis, fatigue failure does not occur even when the number of alternating operation of the automatic press increases, and the natural frequency is predicted for dynamic characteristics.

The result of the previous work leads to the idea that the inner area of the hyperbolic shell generator should be minimized for the cooling tower with higher first natural frequency. In this study the inner area of the hyperbolic shell generator was graphically established under varying height of the throat and angle of the base lintel. From the graph, several shell geometries were selected and analysed in the aspect of the natural frequency. Three representative towers reinforced differently due to different first natural frequencies were analysed non-linearly and evaluated using a damage indicator based on the change of natural frequencies. The results demonstrated that the damage behaviour of the tower reinforced higher due to a lower first natural frequency was not necessarily advantageous than the others

The brake systems are composed of brake disc, brake pad and caliper and, these three parts play an important role for braking. In this study, heat fluid analysis is conducted for five different ventilated disc models, and two piece brake disc model separated in rotor and housing is used. In this case, each model has a different number of holes and vent shape. The basic heat flux and braking power equations are applied for the heat fluid analysis. The cooling performance with/without the braking operation is also analyzed for given five models where the material properties and boundary conditions are set to be identical. From our analysis results, it is found that the number of disc holes and ventilated pins strongly influences on the cooling performance.

Determining of the shape in the process of design for natural draught cooling tower is very important, because the shape of hyperbolic shell is respond sensitively to dynamic behavior of the whole cooling tower against wind load. In engineering practice, the geometric parameters have been determining based on the natural frequency. This study analyses influence of the tower shell geometric parameters on the structural behavior. For three representative models were selected, they were analyzed based on evaluation of damage by means of nonlinear FE-method. As a result, a hyperbolic rotational shell with the small radius overall was the lowest damage index induced by sufficient capacity of the stress redistribution and thus a wind-insensitive structure.

Unreinforced masonry (URM) buildings are known to be highly vulnerable to seismic loadings. Although significant physical variation may exist for URM buildings that fall into a same structural category, a single set of fragility curves is typically used as a representation of the seismic vulnerability of the URM structures. This study investigates the effect of physical variation of URM structures on their seismic performance level. Variables that describe the physical variation of the structure are defined based on the inventory analysis. Seismic behavior of the structures is then monitored by changing the variables to investigate the effect of each variable. The analysis results show that among the variables considered the seismic performance of URM building depends on the variation of the width, the aspect ratio, and the number of story. The need for further research on the modeling of the connections between the walls and diaphragms and the torsional effect is also addressed.

We report on an all-solution-processed hydrothermal method to control the morphology of ZnO nanostructures on Si substrates from three-dimensional hemispherical structures to two-dimensional thin film layers, by controlling the seed layer and the molar contents of surfactants during their primary growth. The size and the density of the seed layer, which is composed of ZnO nanodots, change with variation in the solute concentration. The ZnO nanodots act as heterogeneous nucleation sites for the main ZnO nanostructures. When the seed layer concentration is increased, the ZnO nanostructures change from a hemispherical shape to a thin film structure, formed by densely packed ZnO hemispheres. In addition, the morphology of the ZnO layer is systematically controlled by using trisodium citrate, which acts as a surfactant to enhance the lateral growth of ZnO crystals rather than a preferential one-dimensional growth along the c-direction. X-ray diffraction and energy dispersive X-ray spectroscopy results reveal that the ZnO structure is wurtzite and did not incorporate any impurities from the surfactants used in this study.

This study analyzes gestation stall structures with high strength concrete. The ANSYS program described in this paper is effective not only because it shows good accuracy but also it shows the goodness of parameter studies by using APDL(ANSYS Parametric Design Language). We have performed the various parameter studies by thickness change. The results is presented by using contours and tables. The analysis results showed that it was effective to increase the height thickness(tz) rather than longitudinal thickness(tx).

In this study, a shape design and an analysis considering structural stability were investigated to develop an icosahedron-based hemispherical modular dome. To design this modular dome, a program that can perform icosahedron shape modeling, modularization of joint connection members, and the analysis of structural stability was developed. Furthermore, based on the adopted numerical model, the eigen buckling mode, unstable behavior characteristics according to load vector, and the critical buckling load of the modular dome under uniformly distributed load and concentrated load were analyzed, and the resistance capacities of the structure according to different load vectors were compared. The analysis results for the modular dome suggest that the developed program can perform joint modeling for shape design as well as modular member design, and adequately expressed the nonlinear behaviors of structured according to load conditions. The critical buckling load results also correctly reflected the characteristics of the load conditions. The uniformly distributed load was more advantageous to the structural stability than concentrated load.

Structural system involves random conditions such as material property, geometric parameters and applied loads. This is caused by either measurement inaccuracy or system complexity and must be designed to withstand the uncertainties, Random structures may be modelled by using the finite element method using Monte Carlo simulation. It can be applied easily to any structural system with random parameters. The aim of this paper is to find the shape optimal design for the cantilever beam with random input variables to the height and response parameters to the displacement and stresses. The probabilistic design is carried out using ANSYS probabilistic design module in a commercial application software and then the optimal design is sequentially solved. An efficient and practical shape optimal design evaluation method is proposed for the design of the cantilever beam shape. The numerical results are obtained where total volume of the beam, stresses and displacements in the beam treated as constraints

An experimental study on the structural behavior of connection types between approach slab and integral abutment has been done for three typical bar connections. Typical hinge style reinforcing bar detail for its connection is preferred in order to accommodate rotation of the approach slab among engineers. However, the straight horizontal bars can be used as connection detail accomodate structural capacity. Total six specimens with three types of rebar detail are tested for direct tensile and bending load. The characteristic structural behaviors are carefully monitored and all the strain gauge data obtained are analyzed. It is shown that the structural performance of all the specimens well exceed its design allowance. Several design suggestions are given based on careful reviews on the experiment.

In this paper. the effects of the aspect ratio on the natural frequency of the advanced composite road structures is studied. The advanced composite structures are too difficult for such design engineers for construction and some simple but accurate enough methods are necessary. Some laminate orientations have decreasing values of  ,  ,  and  stiffnesses as the ply number increases. The plate aspect ratio considered is from 1 to 5. Most of the road structures have large aspect ratios, for such cases further simplification is possible by neglecting the effect of the longitudinal moment terms.

텐세그리티 구조물은 인장력을 받는 연속된 케이블 안에 압축력을 받는 스트럿이 결합된 형태로 구성된다. 텐세그리티 구조물은 자기 응력 상태를 갖는 프리스트레스 핀 접합 구조물에 속한다. 텐세그리티 구조물 설계의 핵심은 평형 배열상태를 구하는 일명 형상탐색 과정이다. 본 논문에서는 세 가지의 효과적인 텐세그리티 구조물의 형상탐색 기법을 제안하였다. 형상탐색과정을 수행하면 평형상태의 내력 밀도와 그에 대응하는 위상을 얻을 수 있다. 이 때 평형상태를 형성하는 적절한 내력밀도 값을 얻기 위해 유전자 알고리즘을 결합한 내력밀도법이 사용되었다. 수치해석 예제를 통해 제안 알고리즘의 효율성을 입증하였다.