The F3D(Free-Form Formwork 3D Printer) technology that manufactures EPS(Expanded Polystyrene) formworks for irregular-shaped concrete structures by 3D printers was developed to reduce the cost and time. Because of weak strength and low elastic modulus of the EPS, structural performance including lateral pressure by fresh concrete of the formwork that consisted of EPS should be investigated. In order to calculate lateral pressures acting on formwork, several variables including sizes, shapes of formwork, tangential force(fricition) between fresh concrete and formwork, and material properties of fresh concrete should be considered. However, current regulations have not considered the properties of concrete, only focused on vertical formwork. Galleo introduced 3-dimensional finite element analysis models to calculate lateral pressure on formwork. Thus, proposed finite element analysis model based on previous studies were verified for vertical formwork and irregular-shaped formwork. The test results were compared with those by FEM analysis. As a result, the test agrees well with the analysis.

본 실험은 횡성지역내 조사료 자급을 위한 귀리(Avena sativa L.)의 채종재배 적합성을 평가하고자 2016년 3월부터 7월까지 강원 횡성 시험포장(전작)에서 수행되었다. 공시품종은 춘파귀리인 ‘하이스피 드’를 이용하여 서로 다른 수준의 파종량과 질소시비량을 통해 출수특성, 생육특성, 수량성 등을 평가하 였다. 이를 바탕으로 횡성 지역 내 채종재배를 위한 귀리의 적정 파종량과 질소시비량을 얻고자 수행되 었다. 파종량 및 질소시비량에 따른 귀리의 출현일수 및 출수일수는 각각 8일, 74일로 모든 시험구에서 동일하게 나타났으며, 출수기 이후 성숙기까지의 소요일수는 12일로 모든 시험구에서 동일하게 나타났 다. 파종량에 따른 귀리의 초장 및 수장은 파종량 130kg/ha 시험구에서 가장 높았으며, 단위면적당 경 수와 수수는 파종량 160kg/ha 시험구에서 가장 높게 나타났다. 1수립수, 1수립중, 천립중(千粒重)과 리 터중은 파종량 100kg/ha 시험구에서 가장 높았으며, 파종량에 따른 종실수량은 파종량 100kg/ha 시험 구에서 4.5t/ha로 가장 높은 수량을 나타냈다. 질소시비량에 따른 귀리의 초장, 간장 및 수장은 질소시 비량 50kg N/ha 시험구에서 가장 높았으며, 경수와 수수는 질소시비량 70kg N/ha 시험구에서 가장 높게 나타났다. 질소시비량에 따른 1수립수, 1수립중, 천립중(千粒重), 리터중은 질소시비량 70kg N/ha 시험구에서 가장 높게 나타났다. 질소시비량에 따른 종실수량은 질소시비량 50kg N/ha 시험구에서 4.5t/ha로 가장 높은 수량을 나타냈다. 채종재배는 종실의 수확이 목적이므로 수확지수와 종실수량을 우선적으로 고려했을때, 횡성지역 내 조사료 자급을 위한 귀리 채종 재배에 있어 적정 파종량은 100kg/ha, 적정 질소시비량은 50kg N/ha가 적합 할 것으로 판단된다.

Composite Floor system infilled with PCM(Phase Change Material) between upper and lower steel plates was developed to apply the steel frame. When steel frames were applied this system, it can absolutely reduce the duration of construction due to dry construction method. However to apply this system as a structural floor member without fire resistance covering, it must have 2 hours fire resistance performance. Because PCM consisted of three quarters of section with thermal insulation performance, fire resistance performance of this floor system was expected to easily have 2 hours fire resistance performance. This paper was to investigate behavior characteristics of PCM infilled floor system at elevated temperature using FEM analysis to develop the fire resistance performance of it.

As demands for freeform structure were gradually increased, researches about various shapes of claddings have been conducted. Particularly, claddings made from concrete easily made complex shapes. Because of this advantage, many researches about manufacturing methods and light weight of concrete mainly have been conducted. For example ALC (Autoclaved Lightweight Concrete) was the most popular claddings that had a great strength without aggregate and were cured at high temperature and pressure conditions. This paper showed multi-layer reinforcement system, exactly 5 layers polymer reinforcement method, that consisted of 3D printing material with low weight and high performance mechanical properties. Finite element analysis were performed to predict the maximum deformations loaded by wind and self-weight. Joints of analysis model were simplified as the pin joint. The variable of this analysis was the material arrangement of 3 layers located at center among exterior layer. Finally, the maximum deformations of analysis results were compared with the limitations of claddings.

This paper investigated impact resistance capacity and failure mode of strengthened column with PROTECT (Poly-Resilience-Oriented hybrid TEChnology plaTe) panel by analytical study. PROTECT panel is the composite panel with two steel plates and nano-composite. In order to perform impact analysis, dynamic properties of concrete, steels and nano-composite were determined. Finite element analysis was performed with these properties under the drop-weight impact. From the FEA, different failure modes corresponding to different columns were derived.

In fire design for floors, the three criteria of stability, integrity and insulation are required for the specified fire resistance duration. Among these, stability is not easy to confirm. For solid prestressed concrete slabs of uniform thickness, Eurocode 2 provides tabulated data and specifies an axis distance to the centroid of strands to achieve particular fire resistance ratings, but it is not clear if this data can be used for a wide range of different prestressed slab profiles. In order to verify the current code-fire ratings for precast prestressed slabs, both simple and advanced calculation methods are investigated. This paper examines the use of calculation methods, accounting for the real behaviour of unprotected simply supported prestressed concrete slabs exposed to the standard ISO 834 fire. The calculated fire resistance of each prestressed concrete slab is compared with tabulated data in Eurocode part 1.2, with detailed discussion.

Numerical models of composite floor systems with various thickness of phase change material and sizes of circular spacers were developed based on finite element analysis. In order to perform a heat transfer analysis, thermal properties of steels were determined and those of phase change material were estimated from experiment results. In addition, the thermal insulation performance of composite floor systems with respect to different thickness of phase change material and sizes of circular spacers was predicted. To verify the validity of analysis, analysis results were compared with vertical furnace fire test results of equivalent conditions. As a result, available thicknesses of phase change material and sizes of circular spacers were proposed to satisfy the thermal insulation criteria of Korean Standards.

With the recent trend to construct high-rise and large buildings, the steel structure system is widely used, but there are not enough studies on the vibration characteristics of the iFLASH system on the buildings. Therefore, in this study, we performed a vibration measurement of the natural frequency and damping ratio in the stage of iFLASH panel, composit, frame completion and cladding completion. The result findings suggest that the damping ratio after the cladding completion has a greater effect on the reduction of the damping ratio, than the stage after the frame completion.

This study investigates the analytical study for developing PEB(Pre-Engineered Building) connection Steel damper. The state-of the art of the steel beam-column seismic connection details were studied previously to develop proper damper for PEB connection. Finite element analysis is performed to develop the prototypes of damper under cyclic load. The study parameters of analysis are the shape, length, thickness, orientation and location of damper. As a result of finite element analysis, three prototype damper details for PEB seismic connection are derived. One is tapered plate on the lower flange of the rafter, another is C-plate on the center of panel zone and the other is brace on the beam-column connection.

This study investigates the analytical study for evaluating impact resistance capacity and failure mode of PROTECT (Poly-Resilience-Oriented hybrid TEChnology plaTe) panel. PROTECT panel is a composite panel with two steel plates and nano-composite. In order to perform impact analysis, dynamic properties of steels and nano-composite were determined. Finite element analysis is performed with these properties under the drop-weight impact. From the FEA, different failure modes corresponding to different impact energy is derived.

To overcome the weakness of spread foundation in large space structure, the research of precast pile for replace spread foundation have been conducted. The new type of joint between PHC pile and steel column is named HAT Joint(Hollow hAlf-sphere cast-sTeel Joint). It connected PHC Pile by bolt that verification of bolt connection should be accomplished. In this paper, pull-out test and flexural performance for HAT Joint to verifying the bolt connection is explained. As a result, the pull-out and flexural capacities of bolt were checked to use in real structure. Furthermore, the equation of pull-out strength was proposed.

iFLASH System is new structural floor system which consists of sandwich panels filled with nano-composite. The nano-composite has low specific gravity and high bonding strength with steel plates. The bonding strength is one of important factors for structural performance of iFLASH　System and it can further be improved by surface preparation such as blast metal cleaning. However, using none blast steel plates is recommended since surface preparation generates additional fabrication time and cost. In this study, a bonding strength test and bending experiment were conducted to check feasibility of applying none blast steel plates to iFLASH　System. Moreover, stress in bonding plane between steel plates and nano-composite was analytically evaluated by finite element method. Consequently, flexural capacity of the specimen was 11% higher than theoretically calibrated value and its flexural behavior was structurally efficient without defect of bonding.

This paper presents a foundation pile to steel column connection that can resist large magnitude of moment and that can be easy installed. The developed joint has spherical shape and it is given the name HAT joint to mean Hallow half-sphere steel joint. Four types of HAT joints are developed. Namely, H-type, T-type, P-type and K-type. In this paper I will talk about the performance assessment of T-type(Tube Column) and P-type(Pile Column) of HAT joints with finite element analysis and experiment on a full scale model is presented.

In Part I, we disccussed of joint between PHC pile and steel column in foundation of large space structures, one prototype of a joint of PHC pile to steel pipe column was suggested on the basis of analytical studies. In this paper, I explain the Joint of PHC pile to steel tube column and more detail of analysis

To overcome disadvantages of usual spread foundation in large space structure, some prototypes of a joint of the PHC pile to steel pipe column that directly connects a column to a PHC pile are analytically studied. With the consideration of strength requirement and stress concentration of joint of the PHC pile to column, we suggest the most appropriate one.

SAFE damper is a hybrid damper which is comprised of a friction damper and a metallic damper. These two dampers combine to resist external energy in stages. Under minor earthquake loads, the friction damper operates alone. However, the friction damper and metallic damper dissipate the energy together when a severe earthquake occurs. In comparison with other methods for seismic retrofitting, the SAFE damper has many advantages. The SAFE damper doesn’t cause damage to façade of the building, and the construction period can be reduced when retrofitting. This paper describes experiments evaluating the structural performance of the SAFE damper. From the results, it was found that the structural performance of a conventional RC bare frame can be significantly improved by the installation of the SAFE damper.

To improve the noise and vibration problems of the existing public parking systems, new floor system was proposed. This system consists of the Sandwich Plate System(SPS), steel beam and post-tensioned steel tendons. To verify the dynamic characteristics such as the natural frequency and damping ratio of the system, the free vibration test was performed. Test results showed that the natural frequency of the SPS composite beam was 23.8Hz and it was increased by 3.8% by installing the post-tensioned tendons. The damping ratio of the specimen with tendons was about 1.64%.

As the occurrence rate of terror and hazard is increasing throughout the world, GSA, DoD, and FEMA are proceeding a study about mitigating the damage of terror. Korea is no more a safe place from the terrorist's threat, so we need to make measures against them. In this study we developed modified RVS System by revising some items to adjust the system to the domestic condition and conducted a risk assessment on several tall buildings in Korea. By using IRVS system which is developed by DHS, we also carried out the risk assessment. Comparing the results between RVS with IRVS, we performed terror risk evaluation of tall buildings. Through risk assessment of several tall buildings, we analyzed key factors of each scenarios and suggested the mean value of each items, so we would like to help the counter-terrorism in the design phase.