A study has been conducted on the structural analysis to reduce the light weight of the electric vehicle rotor shaft. ANSYS Static Structural was used for structural analysis. For weight reduction, the solid shaft was converted into a hollow shaft. The yield strength of the existing material SCM 440 is 655MPa, but to increase its safety, the yield strength is changed to 1,030MPa with SCM822H. At this time, weight reduction of about 47% was achieved. The resonance frequency of the rotor shaft was determined by vibration analysis and the structural safety was analyzed.

The office building more than 3,000㎡ of the total floor area should be needed to improve the energy efficiency based on government's recommendation. In this study, the new composite panel with structural function is conducted to check the thermal conductivity for application of exterior wall. The thermal transmittance was calculated by dynamic analysis to consider the thickness of insulation only per locations based on design criteria. The simulation program for the analysis was used TRISCO Radcon module, which has a function of a steady-state 3-dimensional heat transfer analysis.

본 연구에서는 NURBS 기반 아이소 지오메트릭 쉘 해석을 위해 다중 패치 해석 모델을 정식화하였다. 기존 연구를 통해 개발된 단일 패치로 구성된 전단 변형을 고려한 쉘 요소에 대해 일반 좌표계에서 기하학적으로 엄밀한 쉘 구조물의 아이소지오메트릭 해석 모델을 도입하고 매개변수 연속성을 고려하여 다중 패치 모델로 확장하였다. 인접 곡면의 노트 요소가 결합 경계를 통해 조화를 이루는 경우에 대해 0차와 1차 매개변수 연속성 조건을 고려하였으며, 두 패치 간 마스터-슬레이브 관계를 정립하여 종속된 한 곡면의 자유도를 상대 곡면의 자유도로 표시하여 모델 크기를 줄이면서 두 곡면을 결합하였다. 다중 패치 쉘 예제에 대해 0차와 1차 연속성 조건을 각각 적용하여 구조해석을 수행하여 1차 연속성 조건의 주요한 특성들을 확인하였다. 또한 각 연속성 조건에 대한 해의 수렴 특성을 검토하였으며 결합 경계에서의 두 패치의 연속성을 확인하였다.

A parametric study was carried out to gain an insight about structural performances considering abnormal behavior effects in high strength steel pipe strut system. Six load cases were considered as undesirable deflections of strut structures, which are basic load combination, excessive excavation situations, impact loading effects, additional overburden loads, load combinations, and 50% reduction of strut length. Subsequent simulation results present various influences of parameters on structural performances of the strut system. Based on the results, we propose methods to prevent unusual behaviors of pipe-type strut structures made of high strength steels.

A finite element impact simulation study was performed to assess structural performances of a guard-rail system for roadside using new steel materials (SS275) in the KS standard. The type SS275 shows an enhanced tensile strength in comparison with the former type SS400. Subsequent simulation results present that the improved model performs much better in containing and redirecting the impacting vehicle in a stable manner. The numerical results for various parameters are verified by comparing different models with dynamic responses determined in the barrier from the crash simulation.

Eccentric axial load tests were carried out to investigate the structural performance of the SIP (Structural Insulation Panel), which is widely used as residential type in Europe and North America. Outside the country, design standards for SIP have been prepared and related research has been carried out variously. However, in Korea, the research on the performance of the structural insulation panel is very small, and the related standard is not provided. In this study, the eccentric axial load was applied after the opening was installed to utilize the structural insulation panel as the structural wall. The size of the test specimen was 1200 × 2400㎜. The number of test specimens was 6, and the size of the openings and the reinforcement method around the openings were used as variables.

In this study, the structural analysis of the structural insulation panels with openings was carried out. The analytical results were compared with those of the previous structural performance tests. The structural behavior of the structural insulation panels subjected to eccentric axial load with the opening size, installation direction as parameters was analyzed through finite element analysis. Through this, we propose an optimal opening shape suitable for the structural insulation panel.

The purpose of this study is to compare and evaluate the safety of the facility using the Abaqus finite element analysis program according to the material characteristics like steel and GFRP.

Cluster of differentiation (CD) 24 or heat stable antigen 24 (HSA) molecule is a mucin-type glycoprotein attached to the cell surface by glycosylphosphatidylinositol (GPI)-anchor, promoting adhesive interactions between cells or in extracellular matrix. The aim of this study was to determine the not yet fully identified porcine CD24 gene and protein structure using computational analysis and to validate variants reported in exons of CD24 gene using direct sequencing. A total of 59 samples belonging to Yorkshire, Landrace, Berkshire, Jeju black pig and wild boar were used in the study. Human CD24 mRNA sequences were used as a reference and subjected to BLAST searches to retrieve the orthologous expressed sequence tags (ESTs) or cDNA sequences against NCBI and Ensemble databases. Assembled ESTs and retrieved cDNA sequences for the porcine CD24 gene were used for specific BLAST search to determine its genomic structure. We found porcine CD24 gene to consist of two exons and a relatively long intron. Second exon of porcine CD24 gene had a long 3’ untranslated region (UTR) and was very similar to that of human, mouse, rat, and sheep. The sequence homology of porcine CD24 protein was 65.38-84.62%, when analyzed with amino acid sequences of rat, mouse, human, cattle, and sheep CD24 protein. N-terminal signal sequence, O-glycosylation sites and GPI-anchoring signal sites were also predicted in pig, which showed these motifs to be evolutionary conserved across the species. Variant analysis in exonic regions of porcine CD24 among the multiple breeds showed that only second exon contained eight SNPs and three insertions in a 3’ UTR. Taken together, this study reports putative porcine CD24 gene and its protein structure using in silico approaches, which will be helpful for any further functional studies.

The aim of this paper is to clarify the structural stability of 30m fly(maximum working radius of 30m) and telescopic boom with composition. In order to reduce the weight and insulate, the boom of special vehicle has a 3-stage telescopic boom of DOMEX960, pocket part of acetal, 2-stage refracting boom of ATOS80, insulation boom of glass fiber composition and effector. In this process, CATIA is applied to create 3D modeling, then ANSYS are performed the structural analysis. The structural analysis is performed for a case where the thickness of the insulating boom of the ATOS 80 is 7[㎜] and the thickness of the insulating boom of the FRP material is 15[㎜] and 16[㎜].

Polysulfone 수지를 사용한 그래핀 복합조성물을 제조하고, 이것들의 멤브레인에 대한 잔류응력과 열전도 특성을 분석하였다. 그래핀을 포함하는 polysulfone 멤브레인의 잔류응력분석은 Si (100) 기판에 스핀코팅으로 10 μm 두께의 막을 도포하여 준비한 시료를 대상으로 하였으며, 잔류응력의 측정은 온도를 승온하고 냉각하는 완전한 1주기 동안 수행하였다. 그래핀을 포함하는 polysulfone 평막을 증류수를 사용한 상전이법으로 제조하여 두께방향과 면방향으로 열전도도를 구분하여 각각 측정하였으며 평막시료의 열전도 이방성을 분석하였다. 그래핀의 구조적 특징에 의해 이를 포함하는 polysulfone 막의 잔류응력은 그래핀 함량이 증가함에 따라 점차로 완화되는 경향을 나타내었고, 열전도특성은 평막형성의 구조적 특성과 그래핀의 고유특성에 의해 두께방향과 면방향의 차이를 확인할 수 있었다.

본 논문은 시공단계에서 가설지주 설치를 요구하지 않는 역삼각 트러스 거더로 보강된 새로운 합성 데크플레이트 시스템을 제안한다. 제안된 시스템은 기존 시스템 대비 증가된 강성과 강도를 보유할 뿐 아니라 절대 층고 변화를 최소 수준으로 낮출 수 있으며 기존의 H형강 및 U형 합성보와 같은 다양한 형태의 합성보 부재와 함께 사용될 수 있다. 제안된 시스템의 시공단계 하중에 대한 구조적 성능을 평가하기 위해 5.5m의 스팬을 갖는 5개의 시험체를 제작하여 현장 조건과 유사한 재하 하중을 단계적으로 적용시켜 실험을 수행하였다. 실험결과로부터 각 시험체 별 하중-변위 그래프를 구해 비선형 3차원 유한 요소해석결과와 비교하였다. 비교 결과 보강 트러스 거더와 데크플레이트 사이에 효율적인 하중 분배가 이루어져 두 구조요소가 잘 일체화되었을 뿐 아니라 시공단계 하중에서의 최대 처짐이 건축구조기준의 제한치를 하회하여 사용성 조건을 잘 만 족시킴을 알 수 있다.

본 연구에서는 역량스펙트럼법을 이용해 얻어진 구조물의 성능점을 확률적으로 평가하는 방법을 제시하였다. ATC-40에 따라 역량스펙트럼법을 이용하여 4층 1경간 철골구조물의 성능점을 산정하였다. 요구스펙트럼을 이용하여 구조물의 성능한계를 초과하는지 여부를 분석하기 위해 구조부재의 소성변형각으로부터 정의되는 구조물의 성능한계에 대해 한계변위를 도출하였다. 또한 설계응답스펙트럼과 유사한 응답스펙트럼을 가지는 인공지진파 30개를 선정하여 스펙트럼 가속도에 따른 각 성능한계의 초과여부를 통해 fragility curve를 도출하였다. 관측된 초과확률을 이용하여 fragility curve를 도출하기 위해 maximum likelihood method를 사용하였다. 각 성능한계점에 대응하는 설계응답스펙트럼의 응답가속도값에서 성능한계점을 초과할 확률은 존재하는 것으로 확인되었다. 본 방식은 구조물의 성능점에 대해 지진파의 불확실성을 고려한 확률적 평가가 가능하고, 시간증분해석이 필요하지 않아 해석시간을 상당부분 단축시킬 수 있다는 장점이 있다.

본 연구에서는 실대형 실험과 구조해석을 통하여 현장에서 사용되는 기둥-서까래-도리, 기둥-도리-방풍벽 접합부를 적용한 강관 골조 플라스틱 연동온실의 정적 구조 성능을 분석하였다. 실대형 재하실험 결과는 접합부를 강접합으로 가정한 구조해석 결과와 비교하여 구조물의 횡방향 강성과 각 부재의 하중분담률에서 많은 차이를 보였다. 동고 높이에서 측정한 수평변위는 실험과 구조해석의 차이가 40% 이었고 수직변위는 89%의 차이를 보였다. S3 부재의 발생응력을 기준으로 한 각 부재별 하중분담률을 비교한 결과 실험과 구조해석에서 두 배 이상의 차이를 보이는 부재가 있었으며, 하부측벽이음(S2), 기둥 상부(S7) 등 주요 부재의 실험결과가 구조해석의 하중분담률을 재현하지 않았다. 현장에서 사용하는 접합부가 충분한 강성을 확보하지 않음으로써 구조물에 작용하는 외력을 각 부재에 적절하게 전달하지 못했으며 이로 인해 구조물의 강성이 저하되는 현상이 나타났다. 설계 단계에서 일반적으로 구조 해석에 의해 결정되는 구조성능의 신뢰도는 접합부의 특성을 보다 면밀하게 고려했는지 여부에 따라 좌우 될 수 있다. 따라서 온실 구조 성능에 대한 신뢰성을 높이기 위해서는 온실에 사용되는 다양한 접합부를 고려할 수 있는 구조해석 기술의 개발이 필요하며 설계 기준에서 상세 설계 방법을 보다 명확히 규정해야 할 것으로 판단된다.

본 연구에서는 온실의 구조설계용 작물하중을 산정하는데 필요한 기초자료를 제공하기 위하여 각국의 온실구조설계용 작물하중 기준들을 비교분석하고 여러 가지 온실작물들에 대하여 작물하중을 직접 측정하고 분석하였다. 설계 작물하중에 대한 각국의 기준들을 비교분석한 결과 나라들 마다 서로 많은 차이를 보여주고 있으며, 우리나라 기준들은 외국의 기준들을 그대로 인용하고 있는 것으로 나타나 우리나라 실정에 맞는 작물하중 기준이 제시될 필요가 있다고 판단된다. 최대 주당 작물하중이 토마토는 두 가지 온실에서 각각 3.3kgf·plant-1와 3.9kgf·plant-1로 나타났고, 오이는 0.75kgf·plant-1, 가지는 1.9kgf·plant-1, 딸기는 재배베드를 포함하여 2.1kgf·plant-1 으로 나타났다. 단위면적당 작물하중은 토마토가 평균 8.5kgf·m-2으로 나타났고, 오이와 가지는 각각 2.1kgf·m-2 과 2.4kgf·m-2으로 토마토의 하중보다 훨씬 낮게 나타났다. 우리나라 온실설계기준에 제시된 작물하중은 토마토와 오이의 경우 15kgf·m-2으로 본 연구에서 측정된 값보다 훨씬 높았다. 우리나라의 설계기준이 네덜란드의 기준을 그대로 인용한 것으로 판단되기 때문에 이러한 차이를 고려하여 우리나라의 작물하중 설계기준에 대한 재검토가 이루어져야 할 것으로 판단된다. 딸기의 작물하 중은 행잉베드를 포함한 중량이 21.0kgf·m-2로 네덜란드의 설계기준인 30kgf·m-2보다 훨씬 작았다.

This study highlights the theme of safety leadership in railway organization, conducting empirical analysis on the relationship between safety climates, safety leadership, safety behavior, and accident. The empirical test results based on questionnaires received from 223 train drivers working at A subway firm indicated that relationship between CEO's safety philosophy, and safety communication showed a significant positive effect on boss's safety leadership. And boss's safety leadership showed a positive influence on observation belonging to safety behavior, which in turn showed a significant negative relationship with mistake. However, mistake, observation and violation were shown that there are no relationship with accidents.

PURPOSES: In this study, a three-dimensional nonlinear finite element analysis (FEA) model for airport concrete pavement was developed using the commercial program ABAQUS. Users can select an analysis method and set the range of input parameters to reflect actual conditions such as environmental loading.METHODS : The geometrical shape of the FEA model was chosen by considering the concrete pavement located in the third-stage construction site of Incheon International Airport. Incompatible eight-node elements were used for the FEA model. Laboratory test results for the concrete specimens fabricated at the construction site were used as material properties of the concrete slab. The material properties of the cement-treated base suggested by the Federal Aviation Administration(FAA) manual were used as those of the lean concrete subbase. In addition, preceding studies and pavement evaluation reports of Incheon International Airport were referred for the material properties of asphalt base and subgrade. The kinetic friction coefficient between the concrete slab and asphalt base acquired from a preceding study was used for the friction coefficient between the layers. A nonlinear temperature gradient according to slab depth was used as an input parameter of environmental loading, and a quasistatic method was used to analyze traffic loading. The average load transfer efficiency obtained from an Heavy falling Weight Deflectomete(HWD) test was converted to a spring constant between adjacent slabs to be used as an input parameter. The reliability of the FEA model developed in this study was verified by comparing its analysis results to those of the FEAFAA model.RESULTS : A series of analyses were performed for environmental loading, traffic loading, and combined loading by using both the model developed in this study and the FEAFAA model under the same conditions. The stresses of the concrete slab obtained by both analysis models were almost the same. An HWD test was simulated and analyzed using the FEA model developed in this study. As a result, the actual deflections at the center, mid-edge, and corner of the slab caused by the HWD loading were similar to those obtained by the analysis.CONCLUSIONS : The FEA model developed in this study was judged to be utilized sufficiently in the prediction of behavior of airport concrete pavement.

The study analyzed the current status of fisheries port market and presented the direction of developments. The fisheries port market has become increasingly widespread due to the aging of the facilities and the scale of the fish product trade, and the number of distribution workers has also increased. The problems of fisheries port market are as follows. First, the transaction structure was changed as the proportion of aquaculture products increased. Second, the trading structure has changed, but it has failed to keep pace with the changes in the production structure. Third, the volume and amount of fish traded in aquaculture products and fish stocks increased. As a result, the growth rate of the fisheries port market is decreasing and profitability is deteriorating. The development direction of the fisheries port market is as follows. First, it is necessary to standardize the fisheries port market facilities, according to the type of fish products. Second, it needs to diversify its trade targets such as processed fish products and imported fish products. Third, it is necessary to diversify the business of the fisheries port market in order to increase profitability.