• 지질공학
• /
• 제25권2호
• /
• pp.265-272
• /
• 2015

본 연구에서는 서로 다른 스테인레스 재료 조건으로 지진 하중을 받는 대용량 원형 배수지 구조의 유한요소 해석을 수행하였다. 5,000톤 규모 이상의 대용량에 대한 지진하중은 한국표준 규격 (KSB 6283) 규정으로부터 확장하여 산정하였다. 배수지의 대형화로 인한 용량의 증가는 지진하중의 산정에 중요한 영향을 미친다. 다양한 하중 조합에 대하여 도출한 수치해석 결과는 용량의 변화 및 서로 다른 스테인레스 강종 등의 변수와의 상호작용 특성을 보여준다. 또한 다양한 하중 조합에 따른 대용량 원형 배수지의 구조적 성능을 평가하였다.

• 유통과학연구
• /
• 제13권7호
• /
• pp.41-51
• /
• 2015

Purpose - This study analyzes loading efficiency by loading pattern for package standardization and reduction of logistics costs, along with the creation of revenue for the revenue review panel (RRP) of Membership Wholesale Clubs (MWC). The study aims to identify standard dimensions that can help improve the compatibility of the pallets related to display patterns preferred by the MWC and thereby explore ways to enhance logistics efficiency between manufacturers and retailers through standardization. Research design, data, and methodology - The study investigates and analyzes the current status based on actual case examples, i.e., manufacturer A and Korea's MWC (A company, B company, and C company), and thus devises improvement measures. To achieve this, the case of manufacturer A delivering to MWC was examined, and the actual pallet display patterns for each MWC were investigated by visiting each distribution site. In this study, TOPS (Total Optimization Packaging Software, USA) was used as the tool for pallet loading efficiency simulations the maximum allowable dimension was set to 0.0mm to prevent the pallet from falling outside the parameters, and the loading efficiency was analyzed with the pallet area. In other words, the study focused on dimensions (length x width x height) according to the research purpose and thereby deduced results. Results - The analysis of pallet loading patterns showed that the most preferred loading patterns for loading efficiency according to product specification, such as pinwheel, brick, and block patterns, were used in the case of the general distribution products, but the products were configured with block patterns in most cases when delivered to MWCs. The loading efficiency by loading pattern was analyzed with respect to 104 nationally listed standard dimensions. Meanwhile, No.51 (330 × 220mm) of KS T 1002 (1,100 × 1,100mm) was found to be the dimension that could bring about an improved loading efficiency, over 90.0% simultaneously in both the T-11 and T-12 pallet systems in a loading pattern configuration with the block pattern only, and the loading efficiency simulation results also confirmed this as the standard dimension that can be commonly applied to both the T-11 pallet (90.0%) and the T-12 pallet (90.7%) systems. Conclusions - The loading efficiency simulation results by loading pattern were analyzed: For the T-11 pallet system, 17 standard dimension sizes displayed the loading efficiency of 90.0% or more as block patterns, and the loading capacity was an average of 99.0%. For the T-12 pallet system, 35 standard dimension sizes displayed the loading efficiency of more than 90% as block patterns (the average loading efficiency of 98.6%). Accordingly, this study proposes that the standard dimensions of 17 sizes with the average loading efficiency of 99.0% should be applied in the use of the T-11 pallet system, and those of 35 sizes with the average loading efficiency of 98.6% should be reviewed and applied in the use of the T-12 pallet system.

• 한국환경과학회지
• /
• 제17권4호
• /
• pp.397-403
• /
• 2008

The purpose of this study is to investigate weighted compaction density according to a leading density in truck, a compaction density of solid waste and composition ratios of solid waste fur calculation of a capacity of the landfill sites. The experiments for calculations of in-place density at landfill site have been conducted in S landfill site at B City. The size of vessel for measuring the compaction density was $1m^3(1m{\times}1m{\times}1m)$. The experiment tests have been carried out methods (1 time for bulldozer and 4 times for compactor) that do contain all of specification at the landfill site. Average of the loading density at the landfill site was $0.264\;ton/m^3$ ($0.113{\sim}0.487\;ton/m^3$). When the loading density for each compositions was compared, the composition of the highest average loading density ($0.474\;ton/m^3$) was miscellaneous wastes. The composition of the lowest average loading density ($0.120 ton/m^3$) was general solid waste. The reported results indicated that the compaction density at the landfill site was $0.538\;ton/m^3$, which was calculated with weighted incoming ratios of compositions. The ranges of the density for each composition were from $0.021\;ton/m^3$ to $0.221\;ton/m^3$. When the compaction density for each composition was compared, the composition with the highest average compaction density ($0.221\;ton/m^3$) was miscellaneous wastes. The composition with the lowest average compaction density ($0.021\;ton/m^3$) was general solid wastes.

• 전기학회논문지P
• /
• 제65권4호
• /
• pp.298-302
• /
• 2016

Currently, logistics are in small quantities and in diverse forms, and the amounts are continuously increasing. Railway logistics however are losing their market share every year mainly due to low operation speed and loading time, which means the trucks are covering the most of the freights. In order to solve these situations, this paper proposed the high speed freight train as working multi-modality with other modes to make effective transshipment. The high speed freight train has maximum operation speed of 300km/h and electric power to run centralized power supply. There are large dual door system, bogie system covering fluctuating load of 15[ton], automatic loading device, ULD(unit load device) bed and ULD locking system in this freight rolling stock. We calculated the performance of powering and braking capacity for this train and proposed how many vehicles are composed of train set. The results in this paper can help to make a decision to define the technical specification of High-speed freight train for the efficiency of rail freight service.

• 대한용접접합학회:학술대회논문집
• /
• 대한용접접합학회 2006년도 춘계 학술대회 개요집
• /
• pp.94-96
• /
• 2006

Recently, steel structures have been increasing because of its brilliant features. In general, cracks and corrosion are produced due to the numerous environmental factors in steel structures. However, the validity of repair method for the damaged steel structures has not been fully verified because of its lack of safety and reliability after application. Moreover, repair method by welding inevitably involves cutting and welding processes and reliability for the safety during the processes has net been established yet. Therefore, this study carried out experiments on the fatigue strength of repair welded joints of old steel bridge to investigate the fatigue characteristics in the repair welded joints. Fatigue tests were conducted by 250kN capacity MIS with the frequency of 5Hz under amplitude loading. From the results, it is known that fatigue strength grade of the repair welded joints was satisfied with C grade which specification requires.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
• /
• pp.331-332
• /
• 2012

Structural steel has been used as a primary materials to columns and beams since 1960's in Korea with an advantages of excellent of load-bearing capacity and design flexibility, and faster construction. However, if the steel columns made of structural steel exposed to fire the load-bearing capacity is going down steadily and finally reach to collapse. Therefore, building regulation requires fire resistance according to building occupation, scales. The fire resistance can be evaluated two categories. One is prescriptive method that is based on building regulation, specification and so on and the other is performance-based fire engineering method. The latter can be designed based on scientific and engineering consequences. The easiest evaluation way using the fire engineering design is comparing to the limiting temperature and maximum temperature calculated based on heat transfer theory. If the limiting temperature of a column exceeds the maximum temperature of it, the column can carry the load during the fire. Therefore, the database of limiting temperature is very essential for evaluation of column. In this paper, to build the database of column made of rectangular hollow sections 8 fire tests with loading were conducted and the relation between the limiting temperature and the applied loads showed in reverse proportion.

• 한국콘텐츠학회논문지
• /
• 제20권11호
• /
• pp.669-675
• /
• 2020

본 연구에서는 헬리컬파일의 지지력 특성 규명을 위하여 현장재하시험을 통하여 얻은 실측 지지력과 이론식에 의해 산정된 예측 지지력을 비교 분석하였다. 헬리컬파일은 중공형 축에 중공형 축보다 직경이 큰 하나 혹은 다수의 나선형 원판을 부착시킨 형상의 파일이다. 헬리컬파일은 굴삭기에 부착된 회전관입기를 사용하여 파일을 지반에 회전 관입시키기 때문에 항타와 굴착이 필요한 다른 말뚝에 비해 소음이 작고, 비교적 소형 장비로 시공이 가능하여 공간이 협소한 도심지에서도 시공이 용이하다. 최근 들어 헬리컬파일을 적용한 기초 공법의 설계와 시공이 많이 실시되고 있으나 헬리컬파일의 지지력에 관한 연구는 설계와 시공 사례에 비하여 아직 미진하다. 현장재하시험은 이음부, 헬리컬파일의 규격, 재하시험의 종류, 그라우팅 실시 여부를 변수로 총 10회 실시하였다. 이론식에 의한 말뚝의 예측 지지력은 Individual bearing method와 Cylindrical shear method을 통하여 산정하였다.

• 한국지진공학회논문집
• /
• 제7권3호
• /
• pp.31-38
• /
• 2003

1992년 도로교 설계기준의 내진설계규정이 도입되기 이전에 건설된 대부분의 교각은 소성힌지구간에서 주철근의 겹침이음이 이루어졌다. 그러나 비탄성 반복하중하에서 겹침이음부의 갑작스런 취성파괴가 발생할 수 있다. 이 연구는 반복하중을 받는 주철근이 겹침이음된 철근콘크리트 교각의 비선형 이력거동과 연성능력을 해석적으로 파악하는데 그 목적이 있다. 이를 위해서 비선형 해석프로그램인 RCAHEST가 사용되었으며 겹침이음된 철근의 거동을 예측하기 위해서 겹침이음 철근요소를 개발하였다. 또한 겹침이음된 철근의 최대 철근응력과 슬립이 고려되었다. 이 연구에서는 주철근의 겹침이음을 갖는 철근콘트리트 교각의 내진성능평가를 위해 제안한 해석기법을 신뢰성 있는 연구자의 실험결과와 비교하여 그 타당성을 검증하였다.

• 한국구조물진단유지관리공학회 논문집
• /
• 제8권1호
• /
• pp.211-220
• /
• 2004

본 연구의 대상은 익스팬션 앵커에 해당하는 국내산 중량물 앵커(heavy duty anchor)와 웨지 앵커(wedge anchor)에 대해서 앵커설계의 기초가 되는 콘파괴를 중심으로 무근콘크리트에서의 인발실험으로 국한된다. 각각의 앵커에 대해 ACI 349-90 설계기준과 EOTA (European Organization for Technical Approval) 기준의 근거인 CCD 설계방법에 의해서 연단거리를 변수로 한 앵커의 콘파괴강도 예측값과 실험값을 비교 평가하고자 하며, 이 연구를 근간으로 하여 국내산 앵커를 구조설계에 적용시 기초자료 제공을 목적으로 한다.

• Steel and Composite Structures
• /
• 제50권6호
• /
• pp.675-688
• /
• 2024

Cold-formed steel (CFS) is prone to buckling failure under loading. Lightweight concrete (LC) made of lightweight aggregate has light weight and excellent thermal insulation performance. However, concrete is brittle in nature which is why different materials have been used to improve this inherent behavior of concrete. The distortional buckling (DB) performance of cold-formed steel-lightweight concrete (CFS-LC) composite columns was investigated in this paper. Firstly, the compressive strength test of foam concrete (FC) and ceramsite concrete (CC) was carried out. The performance of the CFS-LC members was investigated. The test results indicated that the concrete-filled can effectively control the DB of the members. Secondly, finite element (FE) models of each test specimen were developed and validated with the experimental tests followed by extensive parametric studies using numerical analysis based on the validated FE models. The results show that the thickness of the steel and the strength of the concrete-filled were the main factors on the DB and bearing capacity of the members. Finally, the bearing capacity of the test specimens was calculated by using current codes. The results showed that the design results of the AIJ-1997 specification were closer to the experimental and FE values, while other results of specifications were conservative.