• Steel and Composite Structures
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• 제13권2호
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• pp.171-185
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• 2012

The calculation of fire resistance for a composite structural element comprises the calculation of the temperature within its cross-section and of the load bearing capacity, considering the evolution of the steel and concrete mechanical properties, function of the temperature. The paper proposes a method to calculate the bending capacity under ISO fire, for Slim Floor systems using asymmetric steel beams, with a wider lower flange or a narrow upper flange welded onto a half hot-rolled profile. The temperatures in the cross-section are evaluated by means of empirical formulas determined through a parametrical analysis, performed with the special purpose non-linear finite element program SAFIR. Considering these formulas, the bending capacity may be calculated, using an analytical approach to determine the plastic bending moment, for different fire resistance demands. The results obtained with this simplified method are validated through numerical analysis.

• 국제초고층학회논문집
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• 제9권2호
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• pp.187-195
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• 2020

As deep decks are commonly used in construction fields and high-rise building. etc, the slim floor system is increasingly employed. But, the drawback of the slim floor system is that the use of 250 mm deep decks in a structure having a clear span of more than 6 m because of deflection and flexural buckling. This study suggests a non-support construction method where tendons are installed in the deep decks of the slim floor structure to introduce preload in order to control deflection in a structure having a clear span of 9 m. Loading tests were conducted to verify the composite effect and flexural capacity of the preloaded deep deck composite slab and evaluate the serviceability of the supportless construction method. The results showed the complete composite behavior of the preloaded deep deck composite slab with tendons. The specimens satisfied deflection limit and the working load was approximately 25% of the maximum load capacity. It is deemed that the cross-sectional area and yield strength of the deck plate should be taken into account in slab design and the yield strength and diameter of the tendon should be determined with the pre-tension taken into consideration.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 추계학술대회 논문집
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• pp.119-128
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• 1998

An electromagnets and a single-sided linear induction motor(SLIM) are used for suspension and propulsion equipment respectively. The electromagnets and SLIM are installed in the same frame, called a bogie, to reduce the volume under the vehicle floor and to raise the response charateristics to follow the track. Then the 3-dimensional forces(thrust force, normal force, side force) generated by SLIM direct]y affect the suspension system as the disturbance force. Moreover, in the running condition, the gap length variation in the electromagnets is the same as the SLIM. Therefore, the mutual interaction between the electromagnets and the SLIM is an important problem to realize the smaller gap length. In this paper, the dynamic interaction is analyzed and confir

• 한국의류학회지
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• 제16권4호
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• pp.485-493
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• 1992

Three kinds of tight skirts, slim type, straight type, and semi-tight type were investigated to obtain necessary information about the size of the back slit. Fourteen college students put on these experimental clothes and walked on the flat floor, going up and down the stairs. The dimensions of the back slit were measured by width and length. The stride length was taken from the record of footprints of walking. The correlation between the body measurement, stride length and the size of the back slit was studied. As a result of this experiment, the findings are as follows: 1. The size of the back slits differed from each skirt type at the level of p<0.001. In the case of walking on the floor, the average dimension of the back slit was 14.0 cm long 5.0 cm wide for the slim type,9.5 cm long 2.8 cm wide for the straight type and 2.1 cm long 0.5 cm wide for the semi-tight type. 2. In the case of walking on the stairways, the average dimension of the back slit was 16.0 cm long 5.8 cm wide for the slim type, 12.4 cm long 3.9 cm wide for the straight type and 3.1 cm long 1.1 cm wide for the semi-tight type. 3. The correlation between the height (stature, waist height, knee height) and the size of back slit was 0.3 to 0.6. The correlation between the girth (waist, hip) and the size of back slit was 0.3 to -0.5. 4. The correlation between the stride length and the size of back slit was 0.76 for the slim skirt, 0.56 for the straight skirt, 0.28 for the semitight skirt.

• 한국공간구조학회논문집
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• 제16권4호
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• pp.53-58
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• 2016

SLIM AU(A plus U-shaped) composite beam was developed for reducing the story height in the residential buildings, and saving the cosrtuction cost of floor structures. Structural performance and economic feasibility of the composite beam have been sufficiently approved through the structural experiments and the analytical studies. However, the verification for fire safety is necessary for the practical application of the composite beam. The fire resistance tests with and without loading were performed for the fire safety verification, and the test results were summarized in this paper.

• 한국화재소방학회논문지
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• 제25권1호
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• pp.63-71
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• 2011

비대칭 H형강을 활용한 슬림플로어의 경우, 상대적으로 열전달 속도가 낮은 콘크리트에 강재가 매립된 형상으로 설계되어 화재조건에서 강재의 강성저하를 최소화 할 수 있는 형상으로 설계되었다. 그러나 비대칭 H형강의 하부플렌지는 화재에 직접적으로 노출되므로, 이 부분에 대한 내화피복을 적용하여 슬림플로어 보의 내화성능을 최대한 확보할 수 있는 방안을 모색하고자 하였다. 실험계획은 재하 하중비 0.4와 0.3을 조정하여 하중조건에 따른 내화성능을 비교하고자 하였고 철근보강에 따른 내화성능 향상효율, 내화피복을 적용하였을 경우의 180분 내화성능 확보 유 무를 분석하고자 실험을 수행하였다. 하중비 변화에 따른 실험체를 비교한 결과, 0.1 의 하중비를 낮출 경우 내화성능은 12분 차이가 나며, 처짐격차는 39mm였다. 철근보강에 따른 영향은 12분정도의 내화성능 향상이 가능하며, 최대 102.4mm의 처짐이 제어된다.

• Steel and Composite Structures
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• 제26권4호
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• pp.485-499
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• 2018

In this paper, a hollow steel tube (HST) shear connector is proposed for use in a slim-floor system. The HST welded to a perforated steel beam web and embedded in concrete slab. A total of 10 push-out tests were conducted under static loading to investigate the mechanical behavior of the proposed HST connector. The variables were the shapes (circular, square and rectangular) and sizes of hollow steel tubes, and the compressive strength of the concrete. The failure mode was recorded as: concrete slab compressive failure under the steel tube and concrete tensile splitting failure, where no failure occurred in the HST. Test results show that the square shape HST in filled via concrete strength 40 MPa carried the highest shear load value, showing three times more than the reference specimens. It also recorded less slip behavior, and less compressive failure mode in concrete underneath the square hollow connector in comparison with the circular and rectangular HST connectors in both concrete strengths. The rectangular HST shows a 20% higher shear resistance with a longer width in the load direction in comparison with that in the smaller dimension. The energy absorption capacity values showed 23% and 18% improvements with the square HST rather than a headed shear stud when embedded in concrete strengths of 25 MPa and 40 MPa, respectively. Moreover, an analytical method was proposed and predicts the shear resistance of the HST shear connectors with a standard deviation of 0.14 considering the shape and size of the connectors.

• 한국강구조학회 논문집
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• 제16권5호통권72호
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• pp.575-586
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• 2004

본 논문은 새롭게 개발된 춤이 깊은 데크 플레이트(이하 Deep Deck) 및 비대칭 H형강 하부플랜지에 플레이트를 용접한 비대칭 철골보로 구성된 매립형(슬림플로어) 합성보의 웨브면에 개구부를 가진 유공 합성보의 휨성능에 관한 실험적 연구이다. 실험은 철골보 춤(250mm, 300mm), 개구부의 위치 및 가력조건에 따라 5개의 유공 합성보에 대한 단순지지 휨실험 수행하였다. 실험결과, 매립형 유공합성보는 전단연결재를 사용하지 않고도 콘크리트의 면내 부착력에 의해 충분한 합성작용을 하는 것으로 나타났고, 개구부 주변이 콘크리트에 의해 구속되어 개구부의 보강없이 충분한 구조적 성능을 발휘할 수 있음을 확인하였다.

• Steel and Composite Structures
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• 제9권4호
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• pp.349-366
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• 2009

The composite slim beam has become popular throughout Europe in recent years and has also been used on some projects in China. With its steel section encased in a concrete slab, the steel-concrete composite slim beam can provide the floor construction with minimum depth and high fire resistance. However, the design method of the T-shape steel-concrete composite beam is no longer applicable to the composite slim beam with deep deck for its special construction, of which the present design models are not available but mainly depend on experiences. The elevation of the flexural stiffness and bending capacity of composite slim beams with deep deck is rather complicated, because the influences of many factors should be taken into account, such as the variable section dimensions, development of cracks and non-linear characteristics of concrete, etc. In this paper, experimental investigations have been conducted into the flexural behavior of two specimens of simply supported composite slim beam with deep deck. The emphases were laid on the bonding force on the interface between steel beam and concrete, the stress distribution of beam section, the flexural stiffness and bending capacity of the composite beams. Based on the experimental results, the reduction factor of equivalent stress distribution in concrete flange is suggested, and the calculation method of flexural stiffness and bending capacity of simply supported slim beams are proposed.

• 한국공간구조학회논문집
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• 제16권4호
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• pp.133-140
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• 2016

SLIM AU(A plus U-shaped) composite beam had been developed for not only reducing the story height in residential and commercial building, but also saving the cost of floor construction. The structural performance and economic feasibility was sufficiently approved by means of structural experiments and analytical studies. Even though fire resistance of the SLIM AU composite beam was evaluated throughout furnace fire test, the fire performance of the composite beam using finite element analysis is not analysed yet. Therefore the predictions of fire resistance simulations with loading as well as temperature distribution of the composite beam are summarized in this paper.