Recently, environmental problems associated with the excessive use of fossil fuel are hot issue throughout the world. As an alternative energy resource, the importance of renewable energy is continuously rising. Especially, growth rate of photovoltaic energy generation is the best. In this paper, we present the result of investigations pertaining to the development of photovoltaic energy generation system installed on the sea. The system is consisted of photovoltaic energy generation panel, panel supporting structure, and floating structure. In the panel supporting structure, fiber reinforced polymer plastic (FRP) member manufactured by the pultrusion process is used. A floating type PV power generation structures shall be fabricated and this unit structure (I.e., module) is connected to extend to the appropriate size considering safety, workability, and economic efficiency. Developed floating type photovoltaic energy generation system is installed at fish farm in the south coast of Korea.
This study investigates construction practices for expansion joint using fiber net. After completion of underpass construction of concrete action by the ambient temperature, vehicle vibration and cyclic load due to cracking of asphalt layer expansion joint can penetrate broken asphalt and concrete pavement rapidly destroy the pavement.
The existing study on fiber reinforced of the reinforced concrete columns are mainly used to thermosetting resin for evaluate the seismic performance. as compared with thermoplastic resin, thermosetting resin is the advantage of greater strength and stand in high temperature. but, thermosetting resin has many environmental problems about recycling. In this study, better toughness, recyclability and the advantage of rapid construction than thermosetting resin used to the seismic performance evaluation. The existing unreinforced and Superex reinforced concrete compression test specimens experimented with 4 kinds about reinforced repeat. (unreinforced, 1 layer, 3 layers, 5 layers) The test results appear to be increased the maximum load of 98.37% that 5 layers reinforced repeat when compared to unreinforced
This paper describes an evaluation of the in-service structural performance of a glass fiber-reinforced polymer (GFRP) slab bridge. This first all-GFRP slab bridge was installed in Korea on May 2002. The GFRP slab bridge is a simply supported, its length is 10.0 m, and is designed to carry two-lane traffic and has an overall width of 8.0m. The GFRP slab bridge is a sandwich structure with a corrugated core, fabricated by hand lay-up process with E-glass fibers and vinyl ester resins. The assessment of in-service performance for the GFRP slab bridge in 2004, 2011 includes a field load testing identical to that performed in 2002. The assessment indicates that the GFRP slab bridge has no structural problems and is structurally performing well in-service as expected.
Even though the longitudinally stiffened laminated composite plates with closed section ribs should be an effective system for axially compressed members, the existing researches on the applications of closed-section ribs, especially for the laminated composite plates, are not sufficient. This study is aimed to examine the influence of the sectional stiffness of U-shaped ribs on the buckling modes and strengths of laminated composite plates. Applying the orthotropic plates with eight layers of the layup [(0°)4]s and [(0°/90°)2]s, 3-dimensional finite element models for the U-rib stiffened plates were setup by using ABAQUS and then a series of eigenvalue analyses were conducted. From the parametric studies, the minimum required ply thicknesses as well as the buckling strengths were presented for the analysis models. The buckling strengths were compared with the theoretical critical stress equation for simply supported plates based on the Classical laminated plate theory. This study will contribute to the future study for evaluating the minimum required stiffness and optimum design of U-rib stiffened plates
GRP (Glass fiber reinforced polymer plastic) pipes are classified into flexible pipe category because of the structural characteristics of GRP pipes buried underground. Moreover, the ring deflection of GRP pipe is affected by the certain factors such as pipe stiffness, the modulus of soil reaction of backfill materials, and bedding conditions. In this study, we investigated the structural characteristics of the GRP pipes buried underground considering the soil-pipe interaction including bedding angle, pipe stiffness, and soil density used as a backfill material. From this parametric study, it was found that the soil density used for the backfill is the most important factor relating to the ring deflection of the buried GRP pipe.
This paper presents free vibration characteristics of laminated composite plates with different embedded delamination sizes and locations using three-dimensional finite elements. The free vibration analysis using the 3D finite element (FE) delamination model has merits in that it shows better accuracy but also shows the entire mode shape compared to the conventional approaches. This study investigates free vibration characteristics of laminated composite plates containing an various embedded delamination. The numerical results obtained are in good agreement with those reported by other investigators. Specifically, in this paper, attention is paid to the effects of the local vibration mode for various parameters, such as size of delamination, aspect ratio, and location of delamination.
본 연구는 개별적인 반·강접 복합접합부 구조물을 수치해석적인 방법을 통하여 거동성능을 조사하는 대 초점을 두고 있다. 강제 보와 콘크리트 충전기둥 (CFT) 사이에 저탄소 강 구속재와 초탄성 (Super-elastic) 형상기억합금 (SMA) 재료의 구속재를 이용하여 연결한 방식이 제안된 접합부 구조물의 가장 큰 특징이다. 이러한 설계는 초탄성 형상합금을 변형이 많이 일어나는 부분에 인장 바(Bar)로서 설치하여 복원현상을 기대할수 있다. 또한 저탄소 강재 바는 거동에 에너지 소산능력을 향상 시키는 대 기여한다. 반·강접 접합부는 단순한 핀이나 완전구속으로 모델 링이 불가능하므로 해석이나 설계가 실제로는 매우 복잡하다. 하지만 본 연구에서는 제안된 구조물의 장점과 특성 을 검증하기 위하여 정밀한 유한요소(Finite Element) 방법을 이용하여 접합부의 전반적인 거동을 재현하였다.
In this paper, we present the results of experimental investigation pertaining to the structural behavior of Tee joint connection composed of pultruded I-shape FRP members. In this study, we focus on the evaluation of load carrying capacity of Tee joint which appeared frequently to fabricate framed structure composed of pultruded FRP members. Through the experimental investigation moment-rotation relationship is found and the result is used to estimate the rotaion stiffness.
This study investigates the elastic behavior characteristics of GRP pipes reinforced with trapezoidal ribs instead of rectangular ribs. Han(2006) proposed GRP pipe reinforced with rectangular ribs in 2006, to promote buckling strength of the pipe. But it is more difficult to reinforce pipe with rectangular ribs than external corrugated ribs, because of pipe manufacturing process referred to as filament winding. Therefore, This study investigated the elastic behavior characteristics of the GRP pipe reinforced with trapezoidal ribs for simplifying analysis approach of external corrugated ribs.
The purpose of this study is to analyze flexural strengthening capacity of steel structures using composite materials through the experiment. Until now, A Flexural capacity reinforcing method of steel beams has been used by steel plate appending. The conventional method due to the increase in weight of the reinforcement reduces operation efficiency and welding process cause discomfort which due to the interference of other process. But, the specific gravity of AFRP(Aramid Fiber Reinforced Plastic) strip used as reinforcement in this study is less approximately 20% than steel(SS400) and tensile strength of AFRP is s higher approximately 4 times than steel(SS400). In overseas, CFRP(Carbon Fiber Reinforced Plastic) was used with civil steel structures but, it is difficult to find examples of applying AFRP. In this paper, A experiments were carried out as a variable(development length and thickness of AFRP and CFRP) for flexural strengthening of steel structures.
In this study, the performance of a steel-FRP composite bridge safety barrier was evaluated through the vehicle crash test. Glass fiber and polyester resin were used for FRP. The structural strength performance, the passenger protection performance, and the vehicle behavior after crash were evaluated corresponding to the vehicle crash manual. As the result, A steel-FRP composite safety barrier was satisfied with the required performance.
Rehabilitation of existing steel structure attached to a steel because cross-section is generally raising. But when the area of reinforcement increases, also increases the weight of steel can cause degradation of the operations. In addition, welding process cause discomfort which due to the interference of other process. To replace the existing method, there are researches and applications for civil steel structures on the outside. In this study, bond performance of FRP and Steel were tested to reinforce steel structures by using AFRP as well as CFRP.
This study aims at developing a new shape damper and suggestion for seismic silo structure, which contribute to increase significantly seismic performance and constructional efficiency. The suggested N.B.B.D system is more likely to adoptable because it remarkably contribute to save inter-story drift also to have many advantages compared with conventional X or K type braced frame.
The seismic design range for the national public facilities and power plant is expanded such as it becomes the earthquake Disaster Relief Act with the finance since 2008 as the seismic design concept is highly regarded, etc. The reinforcement of the brace is essential for the seismic performance security of the structure which is unable to be satisfied the current seismic design criteria. The tension brace in which the slenderness ratio is big was designed to the unique lateral force resistive element. And the buckling is generated in the first stage and it is unable to exhibit the structural capability. In this research, the buckling strength improvement the reinforcing method of the suggested tension brace tries to be verified through the experiment.
Recently, strengthening and repairing concrete structures are increasing due to the deterioration of concrete infrastructures. Carbon Fiber Reinforced Polymer Plastic (CFRP) system for strengthening concrete structures have emerged as an alternative to traditional strengthening techniques, such as steel plate bonding, section enlargement, and external post-tensioning. CFRP systems offer advantages over traditional strengthening techniques such as lightweight, noncorrosive, and relatively easy to install. In this paper, we present the structural design algorithm for the RC beams strengthened with CFRP sheet based on ACI 440. In addition, structural behavior of strengthened RC beams is investigated by varying the amount of CFRP sheets.
FRP products have been widely used in various fields of industry because of possessing high-strengths, corrosion resistance. Accordingly the waste FRP have also been increased and the effective recycling methods of waste FRP are needed. In this study, polymer mortar specimens were prepared with the various substitution amount of waste FRP powder. For finding the mechanical properties of polymer mortar added with waste FRP powder, compressive strength tests are conducted. From the test, we could find that compressive strength was increased with respect to the amount of waste FRP powder.
This study proposes a hybrid system of fiber reinforced polymer (FRP) and ultra high performance concrete (UHPC) to enhance flexural strength of existing reinforced concrete (RC) slabs. The proposed system is designed to be placed at the top surface of the slabs for flexural strengthening of the sections in both positive and negative moment zones. The enhancing mechanisms of the proposed system for both positive and negative moment regions are presented. Moreover, to prevent the compression in FRP of the enhanced sections in positive moment zone at flexural failure, neutral axis of the sections at failure is enforced to be in UHPC overlay. From this condition, a relationship between design parameters of FRP and UHPC is established.
An FRP(fiber reinforced polymer)-concrete hybrid hollow offshore wind power tower was proposed. To design this new-type wind tower, a design program was developed. It can design optimized sections automatically with the consideration of material nonlinearities. When the outer diameter and requested capacities of the hybrid tower are given, the developed program performs axial force-bending moment interaction analyses for one thousand sections of the tower and suggests ten economically optimized designs. The analysis considers material nonlinearities of concrete and FRP, and the confining effect of concrete. By using the developed program, example design processes were performed for a 5.0MW turbine and a 3.6MW turbine. The designing process was performed for the loads of wind power turbine and wind load. The designed section and analysis results showed the developed program suggested rational and satisfactory section designs.
The Composite structures such as CFT(Concrete Filled Steel Tube) have many advantages compared to the H shape columns, concrete columns. But, CFT columns were reinforced difficult which was members with closed section. When beams size were different around the columns in buildings of various form, the construction was complex that diaphragm was overlapped or inclined. In this study, structural performance comparison of horizontal diaphragm and vertical plates was conducted.