• Bulletin of the Society of Naval Architects of Korea
• /
• v.22 no.1
• /
• pp.31-37
• /
• 1985

In ship's structure, deck and bottom plate are main strength member subjected to the inplane load due to longitudinal bending, i.e. tensile and/or compressive load. The deck and bottom plate are subdivided into many plate members by stiffeners and girders longitudinally and transversely. Since the plate members are thin, it is likely to be collapsed under compressive load, and when we consider the local strength of deck and bottom, the plate members play an important role in the longitudinal strength. Therefore the precise analysis of their compressive ultimate strength is required for the optimal design of ship's structures. In this paper, the modified analytical method using the incremental form of principle of virtual displacement is introduced to determine the compressive ultimate load of plate members. The results by the present method is satisfactory, and the present method is more effective and economical than the finite element method.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1994.10a
• /
• pp.157-160
• /
• 1994

Recently, many studies on the ultra high strength concrete are performed in our country. so, this study is aimed for analyzing the effects for replacement of silica fume and fly ash. As results, slump, slump flow and compressive strength is showed the high values in replacement silica fume. Tensile strength ratio is 1/17 and bending strength ratio is 1/6 for compressive, there are results of the test.

• Journal of the Korean Wood Science and Technology
• /
• v.38 no.3
• /
• pp.178-184
• /
• 2010

This study was carried out to investigate the properties of woodceramics made from woody part of Broussonetia Kazinoki at different impregnation ratios of phenolic resin of 40, 50, 60, 70%. The physical and mechanical properties increased with increasing impregnation ratio. The highest mean values of density, bending strength, Brinell hardness and compressive strength were 0.66 g/$cm^3$, 53 kgf/$cm^2$, 187 kgf/$cm^2$, 126 kgf/$cm^2$, respectively. There were close correlations between density and bending strength, Brinell hardness and compressive strength, and between MOE and MOR.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.10a
• /
• pp.605-608
• /
• 1999

The objective of this research is to examine whether the determination of development length for high strength concrete by the ACI Building Code 318-95 could be applied and the upped limit of compressive strength, 700kg/$\textrm{cm}^2$ is suitable. Eight beam specimens were tested. Each beam was designed to include two bars in tension, spliced at the center of the span. The beams were loaded in positive bending with the splice in a constant moment region. The variables used here were compressive strength and the space of stirrup within splice length. The results indicated that for (c$\div$Ktr)/db of the range of 1.5-2.0 compressive strength up to 800kg/$\textrm{cm}^2$ is acceptable with regard to bond strength and ductility, thus the limit of compressive strength in ACI 318-95 may be extended to 800kg/$\textrm{cm}^2$.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1998.04a
• /
• pp.371-376
• /
• 1998

In this study, the size effect of concrete members subjected to the axial load and bending moment is investigated using a series of C-shaped specimens of which test procedure is similar to those of Hognestad, Hanson, and McHenry's. Main test variable is a size ratio of the specimens(1:1/2:1/4) at the concrete compressive strength of 500kg/㎠. Test results show that the flexural compression strength at failure decreases as the size of specimen increases, that is, the size effect law is present. Model equation is derived using regression analyses with experimental data and it is compared with formulas for compressive strength of cylinders and shear strength of beams without stirrups. Size effects is distinct th following sequence; shear strength of beams without stirrups, compressive strength of C-shaped specimens, compressive strength of cylinders.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.04a
• /
• pp.579-584
• /
• 1999

In evaluating the ultimate strength of a section for a concrete flexural member, the effect of member length is not usually considered, even though the strength tends to decrease with increase of member length. In this paper the influence of specimen length on flexural compressive strength of concrete was evaluated. For this purpose, a series of C-shaped specimens subjected to axial compression and bending moment were tested using four different length-to-depth ratios(from 1, 2, 3 and 4) of specimens with compressive strength of 58 MPa. Results indicate that the reduction in flexural compressive strength with increase of length-to-width ratios was apparent. A model equation was derived using regression analyses on the experimental data. It was also founded that the effect of specimen length on ultimate strain was negligible, but its effect of the ultimate load and the displacement at center of specimen was distinct. Finally more general model equation is also suggested.

• Journal of Ocean Engineering and Technology
• /
• v.9 no.2
• /
• pp.133-140
• /
• 1995

This paper deals with the residual strength characteristics of composite materials under the environment of high temperature and humidity. Two types of GFRP, one with unidirection and randomly oriented, are used to investigate the features of moisture absorption and the residual strength. The results show that, when exposed longterms in high temperature and humidity, the randomly oriented composites is more stable than the unidirection one.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.39 no.4
• /
• pp.75-81
• /
• 1997

This study was performed to evaluate the engineering properties of surlightweight polymer concrete using synthetic lightweight aggregate. The following conclusions were drawn; 1. The unit weight was in the range of 0.849~0.969t/$m^3$, the unit weights of those concrete were decreased by 58 ~ 63% than that of the normal cement concrete. 2. The highest strength was achieved by $P_1$, and compressive strength was increased by 93% and bending strength by 364% than that of the normal cement concrete, respectively. 3. The ultrasonic pulse velocity was in the range of 2, 346~2, 702m/s, which was low compared to that of the normal cement concrete. 4. The dynamic modulus of elasticity was in the range of $1.561{\times} 10{^5}~1.916{\times} 10{^5}kgf/cm^2$, which was approximately 52~98% of that of the normal cement concrete. 5. The compressive and bending strength were increased with the increase of unit weight. But, the dynamic modulus of elasticity and ultrasonic pulse velocity were decreased with the increase of unit weight.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.44 no.5
• /
• pp.79-87
• /
• 2002

This study is performed to examine the physical and mechanical properties of Eco-concrete using rice straw ash for planting. The tests for void ratio, compressive and bending strength with neutralization treatment point, curing condition and coarse aggregate size are performed. The test result shows that the void ratio is decreased with increasing content of rice straw ash. But, the compressive and bending strength are increased with increasing content of rice straw ash. The greatest strength is appeared when neutralization is treated in curing age of 6 days. These Eco-concrete is very useful for planting.

• Journal of the Korean Society for Railway
• /
• v.7 no.4
• /
• pp.319-325
• /
• 2004

In this study, analysis and design programs of bending of RC beams strengthened with fiber sheets are developed by using Visual Basic Language. The program consists two groups, ultimate strength method and nonlinear flexural analysis method. Ultimate strength method regards concrete compressive stress as a rectangular stress block and do not consider tensile stress of concrete and load-deflection curves. On the other hand, nonlinear flexural analysis considers tensile stress of concrete, load-deflection curves, state of stress distribution and failure strain of strengthening material. Also, the analysis method used in this study regards nonlinear flexural stress as compressive stress of concrete. This program can be a good tool for determining the bending strength of strengthened RC beams and estimating the amount of fiber sheets for practical use.