• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 1994년도 가을 학술발표회 논문집
• /
• pp.169-174
• /
• 1994

This paper presents the results of a parametric study on the bearing capacity behavior of a footing located above geogrid-reinforced ground using the finite element method of analysis. A wide range of boundary conditions were analyzed, with varing geogrid design parameters such as depth of geogrid layer, length and siffness of geogrid, and number of geogrid layer, were analyzed. Based on the results of analysis, the optimum geogrid design parameters were determined, which maximize the reinforcing effect of geogrid reinforcement for a given conidition. Furthermore, the mechanistic behavior of a geogrid-reinforced ground subjected to a footing load was discussed using the results of analysis such as stress distribution, propagation of plastic yielding, displacement vector among others.

• 한국공간구조학회논문집
• /
• 제7권3호
• /
• pp.141-151
• /
• 2007

The appearance of many Glass Fiber Reinforced Plastic (GFRP) constructions look like ordinary steel construction, because GFRP has been imitated by the same way with the traditional steel's cross section as well as connection system. In terms of detachable connection, there was not enough appropriate option of GFRP connection, such as a traditional bolt connection for steel and wood structures. Most of all, from material characteristic of GFRP related to the deficient ductility, the shearstress principle of GFRP s not proper for the material property, which causes ineffective and not economic application of material. With this research problem, the innovative and detachable onnection system, which is more considered with appropriate material characteristic for FRP, is developed. Not only short time but also long time research with various connection variations is carried out.

• Computers and Concrete
• /
• 제12권3호
• /
• pp.303-318
• /
• 2013

The purpose of this study is to present different composed material models for reinforced concrete structures (RC). For this aim a nonlinear finite element analysis program is coded in MATLAB. This program contains several yield criteria and stress-strain relationships for compression and tension behavior of concrete. In this study, the well-known criteria, Drucker-Prager, von Mises, Mohr Coulomb, Tresca, and two new criteria, Hsieh-Ting-Chen and Bresler-Pister, are taken into account. It is concluded that the coded program, the new yield criteria, and the models considered can be effectively used in the nonlinear analysis of reinforced concrete beams.

• 동력기계공학회지
• /
• 제9권2호
• /
• pp.57-64
• /
• 2005

This paper is the study on dry sliding wear behavior of carbon fiber reinforced epoxy matrix composites against lay-up orientation. Tests were investigated on the effect of the lay-up orientation, fiber sliding direction, load and sliding velocity when circumstance keep continuously at $21^{\circ}C$, 60%RH. Pin-on-disk dry sliding wear tests for each experimental condition were carried out with a carbon fiber reinforced plastic pin on stainless steel disk in order to search the friction and wear characteristics. The wear rates and friction coefficients against the stainless steel counterpart were experimentally determined and the wear mechanisms were microscopically observed. The effect on friction and wear behavior are observed differently, according to various conditions. When sliding took place against counterpart, the highest wear resistance and the lowest friction coefficient were observed in the $[0]_{24s}$ lay-up orientation at anti-parallel direction.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1995년도 춘계학술대회 논문집
• /
• pp.216-219
• /
• 1995

One of the principal problems encountered in the use of glass fiber reinforced Plastic composites(GFRP) is to establish an active fiber surface to achieve maximum adhesion between resin and fiber surface. In order to develope new process to overcome the disadvantage of chemical agent, we have studied the effect of reactive plasma glass surface treatment on the electrical and mechanical properties of glass fiber reinforced epoxy composites. It is found that the electrical and mechanical characteristics of the composites treated with plasma is improved especially in the dielectric strength by 20% and tensile strength by 15%, whereas the tan $\delta$ is decreased significantly.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1998년도 봄 학술발표회논문집(II)
• /
• pp.525-530
• /
• 1998

The objective of this experiment is to observe the elastic and inelastic behaviors of high-rise reinforced concrete frames with nonseimic details. To do this, a building frame designed according to Korean seismic code and detailed in the Korean conventional manner was selected. An 1:12 scale plane frame model was manufactured according law. Reversed lateral load tests and monotonic push-over test were performed under the displacement control. To simulate the earthquake effect, the lateral force distribution was maintained to be an inversed triangular by using whiffle tree. From the tests, story displacements, lateral story forces, local plastic rotations and the relations between inter-story drift versus story shear are obtained. Based on the test results, conclusions on the characteristics of the elastic and behaviors of a high-rise reinforced concrete frame with nonseismic details are drawn.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
• /
• pp.75-80
• /
• 2001

This paper investigates the flexural behavior of reinforced concrete beams strengthened with externally bonded fiber reinforced plastic (FRP) sheets is investigated in this work. FRP is attractive for strengthening the RC beams due to its good tensile strength, low weight, resistance to corrosion, and easy applicability. A simple and direct analytical procedure for evaluating the ultimate flexural capacity of FRP strengthened reinforced concrete (SRC) beams is presented using the equilibrium equations and compatibility of strains. Upper and lower limits of FRP sheet area to ensure the ductile behavior are established. A parametric study is conducted to investigate the effects of design variables such as sheet area, sheet stiffness and strength, concrete compression strength, and steel reinforcement ratio. The analytical procedure is compared with results of experimental data available in the literature.

• 한국복합재료학회:학술대회논문집
• /
• 한국복합재료학회 2001년도 추계학술발표대회 논문집
• /
• pp.199-205
• /
• 2001

This paper describes the design methodology, manufacturing process, rebar tensile and bending properties. Braidtrusion is a direct Composite fabrication technique utilizing an in-line braiding and pultrusion process. The produced Composite rebar exhibits ductile stress-strain behavior similar to that of conventional steel bar. Various rebar diameters ranging from modeling scale(3m) to full-scale prototype of 9.5mm have been produced Glass Fiber Reinforced Plastics(GFRP) rebar were successfully fabricated at $\phi$8.5mm and $\phi$9.5mm nominal diameters of soild and hollow type using a braidtrusion process. Tensile and bending specimens were tested and compared with behavior of stress-strain of GFRP rebar and steel bar.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
• /
• pp.509-514
• /
• 2001

The Fibre-optic Bragg grating (FBG) sensor is broadly accepted as a structural health monitoring device for Fibre reinforced plastic (FRP) materials by either embedding into or bonding onto the structures. The accuracy of the strain measured by using the FBG sensor is highly dependent on the bonding characteristics among the bare optical fibre, protective coating, adhesive layer and host material. In general, the signal extracted from the embedded FBG sensor should reflect the straining condition of the host structure. This paper presents a theoretical model to evaluate the differential strains between the bare fibre and host material with different adhesive thickness and modulus of the protective coating of the embedded FBG sensor.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
• /
• pp.536-539
• /
• 2004

This paper focues on the flexural behavior of RC beams externally reinforced using Carbon Fiber Reinforced Plastics plates. (CFRP) A non-linear finite element (FE) analysis is proposed in order to complete the experimental analysis of the flexural behaviour of the beams. This paper is a part of a complete program aiming to set up design formulate to predict the strength of CFRP strengthende beams, particularly when premature failure through plates-end shear or concrete cover delamination occurs. An elasto-plastic behaviour is assumed for reinforced concrete and interface elements are used to model the bond and slip.