• 수산해양교육연구
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• 제12권1호
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• pp.22-82
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• 2000

The ship hull construction materials of fishing boat has changed in order that wooden, steel, and fiber glass reinforced plastic(FRP). The fishing boat made from FRP has increased every year because that materials has proved excellent of the characteries for fishing boats construction members. Recently, FRP tend towards evasion for the pollution of air enviroment. Therefore. the materials of fishing boat construction must be exchanged by another one. Aluminium alloys must be recommended for fishing boats construction mateials because that is light weight and corrosion resisting in the sea water. Regulation of the standard of ship hull construction for aluminium alloys fishing boats did not enact laws in the interior now. Therefore, this regulation was studied by the following items. that is Rudder, Bottom construction, Side hull plate construction, Deck plate construction, piller. Water tight bulkhead, Deep tank, Fish tank, Stern construction, Superstructure, Deck house construction, Hatch, Engine room opening, Hatch opening, Bulwark, Welding and Rivet etc. A study on the regulation will be contributed to enact laws for fishing boat construction of aluminium alloys.

• 한국기계가공학회지
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• 제21권7호
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• pp.98-104
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• 2022

Circular sawing and milling are general machining processes used for routing fiber-reinforced plastics (FRP). In this study, the productivity and cutting quality of a circular saw and flat endmill were compared. As a result, the productivity of the circular saw was approximately ten times higher than that of the endmill for the same tool life, and the burr size of the circular saw was 14 times smaller than that of the flat-end mill. The spectrogram analysis of the cutting sound also showed that the acoustic emission of the circular saw was more uniform than that of the flat end mill. Circular sawing is thus a more suitable process for the straight cutting of pultrusion FRP than a flat endmill.

• 한국구조물진단유지관리공학회 논문집
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• 제3권2호
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• pp.199-204
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• 1999

최근에 복합재료는 콘크리트, 집성보와 같은 기존의 구조재를 보강하여 성능을 향상시킬 목적으로 적용되고 있다. 특히, 대규모의 집성보 구조물은 춤이 큰 부재를 필요로 하는데 섬유보강판을 이용하여 보의 상하부를 보강하면 춤을 크게 하지 않고도 보의 강도와 강성을 증가시킬 수 있다. 본 연구에서는 집성보에 유리섬유보강 플라스틱판(GFRP)을 붙여 스팬 중앙에 집중하중을 가한 휨실험을 수행하였고 실험결과를 층간이론을 이용한 수치해석법과 비교하였다.

• 한국농공학회논문집
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• 제58권2호
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• pp.73-82
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• 2016

This study is about development of personal disaster shelters for minimization of the casualties caused by the landslide and steep slope collapse. The objectives of present research is the selection of disaster evacuation facilities utilizing FRP (Fiber Reinforced Plastic) material. For the proper assessment of FRP member, several layers by strength test and the three-dimensional numerical analysis of these FRR member was carried out. As a result, the personal disaster evacuation facility utilizing FRP materials, was found to be of a material that is able to protect the weak person at the time of the collapse of the landslides and steep slopes.

• 복합신소재구조학회 논문집
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• 제5권3호
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• pp.17-22
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• 2014

Fiber reinforced plastic (FRP) structural shapes are readily available in civil engineering applications. Among many manufacturing techniques used for FRP structural shapes, pultrusion process is one of the most widely used techniques in civil engineering applications. Pultrusion is a manufacturing process for producing continuous lengths of reinforced polymeric plastic structural shapes with constant cross-section. Pultruded composites are attractive for structural applications because of their continuous mass production with excellent mechanical properties. This paper presents the results of investigations pertaining to the bolted connection with two bolts for the pultruded FRP (PFRP) structural members. PFRP bolted connection tests were conducted with end distance to bolt diameter ratio ($e_1/d_b$) and two types of bolt pattern such as horizontal (Pattern A) and vertical arrangement (Pattern B). As a result, it is found that the $e_1/d_b$ is recommended as the ratio of 4. In addition, it is also found that the bearing strengths at failure of the Pattern A and Pattern B have a similar value.

• Structural Engineering and Mechanics
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• 제27권3호
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• pp.277-292
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• 2007

Based on the composite finite element simulation and a series of hydrostatic pressure and burst tests, autofrettage effects on strength and deformation of fiber reinforced pressure vessel with metallic liners have been studied in the paper (autofrettage: during the course of one pressure taking effect, the increasing internal stress in metallic liner can surpass the yielding point and the plastic deformation will happen, which result in that when there is no internal pressure, there are press stress in liner while tensile stress in fiber lamination). By making use of a composite finite element Ansys code and a series of experiments, the autofrettage pressure is determined in order to make the aluminium liner be totally in elastic state, under given hydrostatic test pressure. The stress intensity factors of the longitudinal crack in aluminum liner end under internal pressure and thermal loads have been computed and analyzed before and after the autofrettage processing. Through numerical calculation and experiment investigations, it is found that a correct choice for autofrettage pressure can improve the gas-tightness and fatigue strength of FRP vessel.

• 한국전산구조공학회논문집
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• 제19권1호
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• pp.73-83
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• 2006

본 논문에서는 내구성과 수명을 획기적으로 향상시키기 위해 제3세대 건설재료인 섬유강화 플라스틱(FRP) 소재로 제작된 사각형 중공 교량 바닥판의 파괴모드를 실험과 해석을 통해 분석하였다. 재하시험 결과 바닥판의 강축방향의 거동은 파괴 직전까지도 거의 선형탄성적으로 거동한 반면, 약축방향의 거동은 재하초기부터 작은 하중하에서도 큰 비선형성을 보였다. 이 약축방향 비선형성의 원인은 웨브와 플랜지 연결부의 불완전한 일체거동으로 인한 소성거동 때문인 것으로 판단된다. 웨브와 플랜지의 연결부에 소성힌지를 도입한 간단한 구조모델을 이용하여 이를 확인하였다. 접착부의 박리 파괴 가능성도 검토하였으나 이는 대상 중공바닥판의 약축방향 파괴에 직접적으로 관여하는 것은 아닌 것으로 판단된다 약축방향의 구조거동을 개선시키기 위한 방안으로 내부를 폼으로 충전하는 방법을 제시하였으며 그 가능성을 구조해석을 통해 확인하였다.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1272-1277
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• 2009

Since improved capacity for RC bridges has been required due to deterioration or increase in traffic, the deflection of cracked reinforced concrete slabs need to be reconsidered. Strengthening is known as the better way to improve capacity of bridges than reconstructing. In this paper, Fiber Reinforced Plastic (FRP) was introduced as one of the best strengthening methods for civil structures. The structures strengthened with FRPs can improve the strengthening capacity and serviceability. Therefore, CFRP sheet and Glass Fiber-Steel Composite Plate (GSP) in this research were used for strengthening slabs of RC bridges. Experimental data from the strengthening will be helpful to better understand the effect of the strengthening and effective flexural rigidity.

• Design & Manufacturing
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• 제18권3호
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• pp.9-14
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• 2024

Among the various plastic polymer molding methods, thermoplastic resins are most commonly used for mass production due to their suitability for high-volume manufacturing. However, recently, thermosetting resins have been utilized depending on product design and functionality, necessitating appropriate mold design and injection conditions to achieve suitable molded products. Therefore, resin selection must be considered not only in terms of product design but also based on functionality, taking into account the physical and mechanical properties of the resin. Additionally, since the flow characteristics of the resin are critical in injection molding, molding conditions should be set according to the thermal, physical, and rheological properties of the resin.This study focuses on the effects of filler content (glass fiber) in thermosetting fiber-reinforced plastics (FRP), specifically Bulk Molding Compound (BMC) resin, which is crucial for thermal deformation in automotive motor housing products. The resins used in this study include Generic BMC1 resin, BMC1 with 15% glass fiber, and BMC1 with 30% glass fiber. The research employs CAE (Computer-Aided Engineering) to investigate strain under basic conditions for the BMC resin and the strain variations with the addition of glass fiber. It also examines the impact of filler content on injection molding conditions, specifically mold temperature and curing time. Experimental results indicate that mold temperature has the most significant effect among the injection conditions, while the impact of curing time was relatively minor.

• Structural Engineering and Mechanics
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• 제72권5호
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• pp.569-583
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• 2019

Tubular steel sections are widespread all over the world because of their strength and aesthetic appearance. Tubular steel members may exhibit local buckling such as elephant foot or overall buckling under extreme compression load. Recently, external bonding of fiber reinforced polymers (FRP) sheets for strengthening these members has been explored through experimental research. This paper presents three-dimensional nonlinear finite element analysis (FEA) to investigate the structural behavior of strengthening tubular steel members with FRP against local and overall buckling phenomena. Out-of-roundness and out-of-straightness imperfections were introduced to the numerical models to simulate the elephant foot and overall buckling, respectively. The nonlinear analysis preferences such as the integration scheme of the shell elements, the algorithm for solution of nonlinear equations, the loading procedure, the bisection limits for the load increments, and the convergence criteria were set, appropriately enough, to successfully track the sophisticated buckling deformations. The agreement between the results of both the presented FEA and the experimental research was evident. The FEA results demonstrated the power of the presented rigorous FEA in monitoring the plastic strain distribution and the buckling phenomena (initiation and propagation). Consequently, the buckling process was interpreted for each mode (elephant foot and overall) into three sequential stages. Furthermore, the influence of FRP layers on the nonlinear analysis preferences and the results was presented.