• 한국구조물진단유지관리공학회 논문집
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• 제7권2호
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• pp.193-199
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• 2003

This paper presents the results of an experimental research project on 7 Super Deck Plates with continuous or simple beam types. The test parameters included the distance of truss, depth of deck plate and the type of beam. The test results are as follows ; When thickness of deck plate was increased, maximum strength was improved When the distance of truss bar was reduced from 20cm to 15cm, the mean value of maximum load was increased to 1.21 times. Continuous beam shown superior to simple beam, such as 5.03 times high strength, low deflection at yield point.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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• pp.77-83
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• 1998

The most of the design engineers for construction has academic background of bachelors degree. Theories for advanced composite structures are too difficult for such engineers and some simple but accurate enough methods are necessary. The senior author has reported that some laminate orientations have decreasing values of B$_{16}$, B$_{26}$, D$_{26}$, and D$_{26}$ stiffnesses as the ply number increases. Such plates above behave as special orthotropic plates and simple formulas developed by the senior author［1, 3］ can be used. Most of the bridge and building slabs on girders have large aspect ratios. For such cases further simplification is possible by neglecting the effect of the longitudinal moment terms(M$_{x}$) on the relevant partial differential equations of equilibrium. In this paper, the result of the study on the subject problem is presented.ted.d.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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• pp.223-230
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• 1998

The most of the design engineers for construction has academic background of bachelors degree. Theories for advanced composite structures are too difficult for such engineers and some simple but accurate enough methods are necessary. The senior author has reported that some laminate orientations have decreasing values of D$_{16}$, B$_{16}$, D$_{26}$ and B$_{26}$ stiffnesses as the ply number increases. Such plates behave as special orthotropic plates and simple formulas developed by the author can be used. Most of the bridge and building slabs on girders have large aspect ratios. For such cases further simplification is possible by neglecting the effect of the longitudinal moment terms(M$_{x}$) on the relevant partial differential equations of equilibrium. In this paper, the result of the study on the subject problem is presented.ented.d.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1997년도 가을 학술발표회 논문집
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• pp.215-222
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• 1997

A method of calculating the natural frequency corresponding to the first mode of vibration of beams and tower structures, with irregular cross-sections and with arbitrary boundary conditions was developed and reported by D. H. Kim in 1974. This method has been developed for two-dimensional problems including the laminated composite plates and was proved to be very effective for the plates with arbitrary boundary conditions and irregular sections. In this paper, the result of application of this method to the subject problem is presented. This problem represents the building slabs with a kind of passive and active control devices. Any method may be used to obtain the deflection influence surfaces needed for this vibration analysis. Finite difference method is used for this purpose, in this paper. The influence of the modulus of the foundation on the natural frequency is thoroughly studied.

• 산업기술연구
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• 제18권
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• pp.107-115
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• 1998

Many of the bridge and building floor systems, including the girders and cross-beams, also behave a similar special orthotropic plates. Such plates are subject to the concentrate masses in the form of traffic loads, or the test equipments such as the accelerator in addition to their own masses. Analysis of such problems is usually very difficult. Most of the bridge slabs on girders have large aspect ratios. Finite difference method is used for this purpose, in this paper. The result is compared with that of the beam theory.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.457-460
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• 2008

CFRP plates has been established as an effective method for rehabilitation and strengthening of concrete structures. The CFRP reinforcements are bonded to beams and slabs using structural adhesives. Adhesive strength can be affected by environmental exposure. During freezing-and-thawing cycling, temperature-induced stresses in the adhesive layer, due to differential thermal expansion between the CFRP and the substrate concrete, may lead to bond damage and contribute to or cause premature CFRP composite separation. This paper presents the results of experimental program undertaken to investigate the effects of freeze-thaw cycling (from -18 to $4^{\circ}C$) on the behavior and failure characteristics of RC beams strengthened in shear with CFRP plate using acoustic emission (AE) technique.

• Steel and Composite Structures
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• 제49권2호
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• pp.197-213
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• 2023

To investigate the static properties of large high strength bolt shear connector in hybrid fiber-reinforced concrete (HFRC) and normal concrete (NC), eight push-out test specimens with single/double nut and HFRC/NC slabs were designed and push-out tests were conducted. A fine 3D nonlinear finite element (FE) model including HFRC constitutive model was established by using ANSYS 18.0, and the test results were used to verify FE models of the push-out test specimens. Then a total of 13 FE models were analyzed with various parameters including fiber volume fractions of HFRC, bolt diameter and thickness of steel flange. Finally, the empirical equations considering the contribution of polypropylene fiber (PF) and steel fiber (SF) obtained from the regression of the test results and FE analysis were recommended to evaluate the load-slip curve and ultimate capacity of the large high strength bolt shear connector embedded in HFRC/NC.

• 콘크리트학회논문집
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• 제14권5호
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• pp.774-781
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• 2002

본 연구에서는 국내에서 활용하고있는 지간거리 l0m인 실물크기 4개의 싱글티 슬래브의 댑 단부에 대하여 8번의 전단실험을 실행하였다. 시험체는 국내 규준의 주차장을 위한 활하중 500kgf/$m^2$와 매장용도를 위한 활하중 1,200 kgf/$m^2$을 적용하여 설계하였다. 강도설계규준을 모두 만족시키면서 시험체에 적용시킨 변수는 걸이철근의 배근방법을 다르게하여 적용시켰다. 현재 국내에서 활용하는 PCI 배근방법에의한 단면과, 90$^{\circ}$절곡배근, 60$^{\circ}$절곡배근에 대한 각 실험결과를 비교 분석하였다. 1) 5mm깊이 빗질로 거칠게 마감한 플랜지 상부의 모든 시험체는 종국파괴까지 토핑콘크리트와 일체 거동하였다. 강선의 정착구 파괴로 인한 조기 파괴된 하나의 시험체를 제외하고서 주어진 강도규준 설계를 대체로 만족시켰다. 2) 걸이철근의 여러 가지 형태를 변수로 두어 실험한 결과 복부 전단균열과 수직으로 배치된 60$^{\circ}$절곡 배근형태의 시험체가 사용하중과 종국하중에서 가장 우수한 결과를 나타냈으며, PCI 형태의 일반배근, 90$^{\circ}$절곡배근의 순으로 전단성능이 좋게 평가되었다.

• Structural Engineering and Mechanics
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• 제84권5호
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• pp.685-697
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• 2022

Nanotechnology has become one of the interesting technique used in material science and engineering. However, it is low used in civil engineering structures. The purpose of the present study is to investigate the static behavior of concrete plates reinforced with silica-nanoparticles. Due to agglomeration effect of silica-nanoparticles in concrete, Voigt's model is used for obtaining the equivalent nano-composite properties. Furthermore, the plate is simulated mathematically with higher order shear deformation theory. For a large use of this study, the concrete plate is assumed resting on a Pasternak elastic foundation, including a shear layer, and Winkler spring interconnected with a Kerr foundation. Using the principle of virtual work, the equilibrium equations are derived and by the mean of Hamilton's principle the energy equations are obtained. Finally, based on Navier's technique, closed-form solutions of simply supported plates have been obtained. Numerical results are presented considering the effect of different parameters such as volume percent of SiO₂ nanoparticles, mechanical loads, geometrical parameters, soil medium, on the static behavior of the plate. The most findings of this work indicate that the use of an optimum amount of SiO₂ nanoparticles on concretes increases better mechanical behavior. In addition, the elastic foundation has a significant impact on the bending of concrete slabs.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 추계 학술발표회 제20권2호
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• pp.209-212
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• 2008

I형강 접합 절곡 강합성 바닥판은 절곡 바닥판내에 I형강을 매입하여 기존의 현장타설 철근콘크리트바닥판보다 경량화되고 하중저항성능 및 시공성을 향상시킨 강합성 바닥판이다. 현재 일반적인 철근콘크리트 구조물의 유효휨강성에 대한 계산은 도로교설계기준 및 ACI에서 제안하고 있는 방법을 사용하고 있다. 본 논문에서는 도로교설계기준 및 ACI에서 제안된 유효휨강성에 대한 산정 방법과 CEB-FIP MC-90에서 제안하고 있는 방법을 사용해 I형강 접합절곡강합성 바닥판의 유효휨강성을 계산하고 그에 대한 적합성을 평가하였다. 또한 전단연결재의 유 무, 단면의 변화, 부재연결 그리고 일반철근콘크리트보와의 비교등 4가지 실험변수를 두고 총 5개의 실험체를 제작 실험하였고 실험결과와 이론식으로 산정된 휨강성값을 비교,평가하여 실험변수에 따른 휨강성의 변화를 분석하였다. 실험결과 CEB-FIP MC-90에서 제안하고 있는 방법이 ACI에서 제안하고 있는 방법보다 만족스러운 결과를 나타냈으며, 전단연결재가 있고 콘크리트와 바닥판의 부착면적이 많은 경우에 하중저항 성능과 휨강성이 높게 나타났다.