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.

Geotextile tubes are excellent design strategies for both shoreline protection and dewatering of fine materials. A difficulty with regard to designing geotextile tubes is the matching of the appropriate fabric with the site-specific infilled material and the unavailability of a test to determine the soil-geotextile consolidation properties. Existing methods simulate and predict the final tube shape based on the initial and final unit weights of the infill but the time required to reach the final shape or the compatibility of the infill are not being considered. This study proposes an improved hanging bag test to evaluate the compatibility of an infill with the geotextile fabric, and at the same time, to obtain the soil-geotextile consolidation properties. With the obtained consolidation properties, a big prototype simulation was possible, explaining the deformation behavior of the tube in the field. An analytical procedure used in modeling the tube was coupled with the large strain consolidation theory to simulate the filling and dewatering process.

A behavior of FRP(Fiber Reinforced Polymer) panel in a steel frame structure was evaluated through the finite element analysis in this study. In order to numerical analysis, a experimental test results was used to develop a three dimensional finite element model of steel frame specimen. Numerical results of the steel frame specimen was well predicted the experimental behavior of steel frame specimen. Based on the developed three dimensional finite element model of steel frame specimen, the behavior of FRP panel in the steel frame specimen was evaluated. From the numerical analysis results, strength of the steel frame specimen with FRP panel was governed by FRP panel. Also, diagonal compression behavior governed the FRP panel in the steel frame specimen in the numerical analysis results.

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

When reinforcing an existing reinforced concrete beam-column building with a precast concrete panel, special connection between the PC member and the RC member is required to solve the time dependent deformation of the RC member and to receive the large shear forces. The aim of this study is to obtain the shear strength of upper connection between the existing RC beam-column and infilled PC wall panels in experimentally and theoretically. Thus, the static shear loading tests were conducted on the 6 specimens with the plate connection. Shear failure was resulted from the weakest portion of interior PC panel, exterior RC, and the connection, when the PC portion which located at the center of specimen was pulled upward from the bottom. T he experimental result was compared with analytical result from ACI 318M-14 Chapter 17 for the shear strength of post-installed anchor and PCI Handbook 7th edition 6.8 Structural Steel Corbel (PCI Design Handbook 7th edition, 2010) for the strength of cast-in H-beam. The analytical and experimental results show final failure at the same location. The failure loading of experiment showed larger than average 6% to that of the analysis.

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.

PURPOSES: This study is primarily focused on evaluating the effects of the non-linear stress-strain behavior of RAP concrete on structural response characteristics as is applicable to concrete pavement. METHODS : A 3D FE model was developed by incorporating the actual stress-strain behavior of RAP concrete obtained via flexural strength testing as a material property model to evaluate the effects of the non-linear stress-strain behavior to failure on the maximum stresses in the concrete slab and potential performance prediction results. In addition, a typical linear elastic model was employed to analyze the structural responses for comparison purposes. The analytical results from the FE model incorporating the actual stress-strain behavior of RAP concrete were compared to the corresponding results from the linear elastic FE model. RESULTS : The results indicate that the linear elastic model tends to yield higher predicted maximum stresses in the concrete as compared to those obtained via the actual stress-strain model. Consequently, these higher predicted stresses lead to a difference in potential performance of the concrete pavement containing RAP. CONCLUSIONS : Analysis of the concrete pavement containing RAP demonstrated that an appropriate analytical model using the actual stress-strain characteristics should be employed to calculate the structural responses of RAP concrete pavement instead of simply assuming the concrete to be a linear elastic material.

본 논문에서는 온실 구조물의 구조 성능 검토 시 적합한 모델링 방법을 제시하기 위해 대상 온실 구조물을 선정하고 지점 및 접합부 조건 그리고 케이블 요소의 단면적을 변화시켜 가며 파라메트릭 스터디를 수행하였으며, 이들 파라메터의 변화에 따른 대상 구조물의 주요 모드 형상 및 고유진동수 변화를 조사하였다. 또한 대상 구조물에 대해 현장 가속도계 측정법을 이 용하여 상시진동을 계측하여 주요 모드 형상 및 고유진동수를 측정하여 해석 결과와 비교하였다. 이들 비교 결과로부터 대 상 온실 구조물의 해석에 적합한 모델링 기법을 제시하였다.

In this study, refined finite element (FE) analyses intended to evaluate the capacity of the existing water purification plant structures against seismic force are conducted with an aim to predict possibility generating tension crack and compression crushing. The FE models for three types of main plant structures were constructed to take ground condition, boundary condition, and water interaction into consideration for advanced simulation. The nonlinear dynamic analyses were performed by using ground motion data which have been used for seismic design. Both compression crushing and tention crack, which are distributed over concrete plant structures during peak ground acceleration (PGA), are investigated by analyzing failure possibility controlled with the strain limits. After observing FE analysis results, it is possible to predict tenstion cracking which can be found at some parts of the main structure.

This paper is a study on the nonlinear behavior of polyhedron curved space roof as building structures of quasicrystal system. The quasicrystal is made up of two kinds of parallel hexahedrons, and all the line elements of the parallelepiped have the same length. The quasicrystal design grid dome has a pentagonal symmetry and all members have the same length. This paper described form of design gird dome, and showed the analysis conditions. Also, The displacement-load curve is shown through the analysis and we grasped the flow of the load and forces through analysis of design grid dome applied quasicrystal system.

이 연구에서는 p-version 동적무한요소법을 도입함으로써 FE-IE 기법에 기반한 KIESSI-3D 프로그램의 속도향상에 역점 을 두었다. KIESSI-3D의 성능을 평가하기 위해 8가지 실규모 SSI 문제에 대한 수치해석을 수행하였다. 이를 위해 근역지반 모델의 반경( r0 )이 구조물기초 반경(R)의 1.2배, 1.5배, 3.0배인 KIESSI-3D 해석모델을 고려하였다. 또한 SASSI2010 프로그 램을 이용한 SSI 해석을 수행하였으며, 이 결과를 KIESI-3D에 의한 결과와 정확성 및 계산속도를 비교하였다. 수치해석 결 과, 인 KIESI-3D 모델을 사용하면 정확한 해석을 수행할 수 있음을 알 수 있었다. 계산속도 측면을 보면, 새로운 KIESSI-3D의 해석속도는 기존 KIESSI-3D에 비해 최대 25배 빠른 것으로 나타났다.

본 논문에서는 풍력 블레이드와 같이 세장비가 크고 초기 비틀림이 존재하는 복합재료로 구성된 블레이드에 대한 이차원 단면의 차원축소와 복원관계를 이론적으로 기술하였다. 그리고 VABS 이용한 보의 차원축소모델에 대한 유효성을 검증하기 위해 선행연구 모델을 활용하여 기존 연구결과를 수치적으로 비교하였다. 실물과 가장 가까운 날개 구조물 2차원 형상에 단 면해석을 적용하여 정밀한 단면의 이산화를 수행하고 VABS를 이용하여 블레이드의 특성(질량행렬, 강성행렬)을 포함한 1 차원 보 모델링을 수행하였다. 1차원 보 모델을 통해 세장비가 큰 날개 구조물의 거동을 확인하고 내부하중을 계산하여 단 면위치에서 변형률 복원을 수치적으로 계산하고 이산화된 단면에 수치적으로 매핑하여 시각적으로 확인하고 여유마진을 계 산하였다.

1970년대 이후 한국의 빠른 경제성장 동안에 수로나 철도 등 많은 지중구조물들이 건설되었다. 1988년에 내진설계가 의무 화되었으나, 1988년 이전의 지중 구조물들은 내진설계가 반영되지 않았다. 따라서, 이러한 지중 구조물들은 지진이 일어났을 때 안전성을 확보하기 위해 효과적인 내진 보강방법이 필요하다. 그러한 이유로, 본 연구에서는 새롭게 개발된 보강재를 이 용한 RC 박스 지중 구조물 우각부 보강공법의 내진성능에 대하여 분석하였다. 이 공법은 박스구조물 우각부에 Pre-flexed member를 설치하여 외력에 저항력을 증대시키는 원리이다. 타당성을 검증하기 위해서 새로이 개발된 보강재와 기존의 보강 재를 실험과 유한요소해석으로 비교하였다. 유한요소모델에서 강재의 비선형 모델은 J2 Plasticity Model을 기초로 하고 콘 크리트는 CEB-FIP MODEL CODE 1990로 모델링되었다. 또한, 설계반영을 위한 박스 구조물과 보강재와의 합성률을 산정 하였다. 보강재와 박스구조물은 Tie에 의해 완전 부착된 상태의 연결조건 하에서 해석이 수행되었으며, 하중-변위곡선에서 실험과 유한요소해석의 결과가 서로 일치하였다.

This study investigates the safety and life during the fatigue load by the configuration of seat frame. On back frame at seat frame, the life and damage are analyzed. The deformation and equivalent stress are compared with each other through the vibration analysis, The result of this study through the analysis can be applied to develop the automotive seat frame with durabilty and safety.

The objective of this work is to investigate the A-IMS structural defects on the tubular shaft and solid shaft by analyzing the under-fill, metal flow, effective stress and load characteristics. The tubular shaft and solid shaft were designed 6 stage process by upper and lower die. The results were analysed by using a finite elements analysis method. The coefficient of frictions were set Oil_Cold conditions as referred to the analysis library. It was found that the actual under-fill phenomenon was not observed in both tubular and solid shaft. The load values of tubular and solid shaft were 520ton and 255ton, respectively. These values were under the limit of forging machine maximum value.

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.