• Journal of the Korean Geotechnical Society
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• v.31 no.4
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• pp.31-43
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• 2015

A numerical analysis on the effect of increasing tensile stiffness of the geosynthetics on the soil displacement and pile efficiency was conducted. Parametric studies by changing the stiffness of soft soil, internal friction and dilatancy angles of the embankment material, and flexual stiffness of the composite layer including the geosynthetics were carried out. In general, increasing stiffness of the geosynthetics improves the pile efficiency, whereas the amount of its improvement depends on the condition of parameters. In case of the sufficiently low stiffness of the soft soil or high flexual stiffness of the composite layer including the geosynthetics, a noticeable increase in the pile efficiency can be observed. When the stiffness of the soft soil is very low, the increase in the stiffness of the geosynthetics can significantly reduce the vertical displacement in the piled embankment. When the flexual stiffness of the composite layer is sufficiently high, increasing stiffness of the geosynthetics can greatly improve the pile efficiency.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.408-410
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• 2012

In this study, High temperature properties of carbon fiber reinforced composites is performed using strand specimens and resin specimens. As for the tensile test at the different temperature, the tensile modulus of resin specimens decreases slightly until the temperature reaches the glass transition temperature. but the tensile modulus of strand specimens maintains tensile modulus at the room temperature. The tensile strength of resin and strand specimens decreases rapidly until the temperature reaches the glass transition temperature.

• Magazine of the Korea Concrete Institute
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• v.3 no.1
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• pp.79-85
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• 1991

This paper aims at experimentally investigating the relationship between tensile load and average strain in the tension zone of SFRC beam. Also, it is attempted to find post cracking tension behavior of SFRC under tensile loading condition. The tension stiffening test is conducted on the long prizm of SFRC which embeds reinforcing bar in both ends of member. From this study, an empirical equation which represents the tension stiffening effect(i.e.effect of increasing tensile-~3trengthening contnbuted by SFRC when the reinforcing bar embeded in the SFRC member is under tensile loading condition) as a function of the average strain is presented .

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.189-192
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• 2007

The qualification test of rubber product is consisted of uniaxial tensile, pure shear, biaxial and compression test. Uniaxial test result is used for material property of Finite Element Method. Comparison of uniaxial tensile test and analysis satisfied requirement. A study has qualificated result of QLS analysis model for material property of uniaxial test and shear modulus.

• Journal of the Korea Concrete Institute
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• v.25 no.4
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• pp.371-379
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• 2013

This paper investigates the cracking and tension-stiffening behavior of 100 MPa shrinkage-compensated strain-hardening cement composite (SHCC) and conventional concrete tie elements in monotonic and cyclic tension. Strain and surface crack formation of tension ties were monitored with two strain displacement transducers and a photo microscope with a lens of magnification 50 times. Three different cement composites such as conventional concrete, shrinkage-compensated SHCC, and normal SHCC were used in the tie specimens to investigate the influence of the cement composite type on the tension stiffening and cracking behavior. Test results indicated that initial shrinkage of the ultra high-strength cement composites is greatly reduced as the 10% replacement of cement by the shrinkage-compensating admixture based on calcium sulfo-aluminate (CSA). The test results on the SHCC tension ties showed that the first cracking load decreases proportionally to the initial shrinkage strain. Reinforced ultra high-strength SHCC ties with the initial shrinkage compensation exhibited improved tension stiffening and smaller crack spacings, i.e. the reduction in crack width. Cyclic loading did not have a significant effect on tension stiffening and cracking behavior of tension ties with normal concrete and SHCC materials.

• Journal of Korean Association for Spatial Structures
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• v.10 no.2
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• pp.69-76
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• 2010

After obtaining tensile and compressive stiffness as well as shear stiffness of elastomeric seismic isolator experimentally, those stiffness were modeled analytically using nonlinear computer program. To induce tensile stress due to overturning in the seismic isolators of an isolated frame for horizontal force, free vibration simulations generated by large initial displacement were conducted. Since elastomeric seismic isolator is weak for tensile stress, the axial stiffness of isolators shall be included properly in the analytical model to evaluate the uplift phenomenon of elastomeric seismic isolator.

• Journal of the Korea Concrete Institute
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• v.22 no.6
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• pp.859-866
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• 2010

To overcome weak and brittle tensile characteristics of concrete, many studies have been conducted on fiber reinforced concrete (FRC). Recently, high performance fiber reinforced cementitious composites (HPFRCC), which shows strain hardening behavior, has been actively investigated. However, most of the studies focused on the material behavior of HPFRCC itself. Only a few studies have been conducted on the tensile behavior of HPFRCC with steel reinforcement. Therefore, a tension stiffening test for HPFRCC members has been conducted in this study in order to investigate the effect of a reinforcing bar on the tensile behavior of HPFRCC. Tensile stress-strain relationship of HPFRCC has been derived from the tests. The HPFRCC resisted tensile stress continuously from the first cracking to the yield of reinforcing bar. Through the comparison with the tensile behavior of HPFRCC members without a reinforcement, it was shown the tensile strength and capacity of HPFRCC were reduced due to the combined effect of the high shrinkage of HPFRCC, restraining effect of steel reinforcement, and the strain hardening behavior of HPFRCC. It is expected that the tension stiffening test results can be useful for an application of HPFRCC with steel reinforcement as structural members.

• Journal of the Korean Geotechnical Society
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• v.32 no.6
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• pp.5-16
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• 2016

In the geosynthetics-reinforced piled embankment the effects of soft soil stiffness, friction angle of the fill material, tensile stiffness of geosynthetics, and height of the embankment on the load transfer soil arch measured by the critical height were numerically investigated. Results from parametric studies show that the magnitude of the soft soil stiffness is the most influencing factor on the critical height. The contour charts of the critical height with respect to the combination of the soft soil stiffness and other parameters were presented. The charts show that the critical height sensitively varies with the combination of the soft soil stiffness and the height of embankment. Under the sufficiently low stiffness of soft soil, the critical height sensitively varies with the friction angle of the fill material. Once the geosynthetic layer is placed, however, the magnitude of the tensile stiffness of the geosynthetic layer hardly influences the critical height of the soil arch.

• Journal of Korean Society of Steel Construction
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• v.19 no.2
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• pp.201-210
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• 2007

Double-angle connections should be designed with enough stiffness and strength to properly resist various applied loads. Therefore, structural engineers should be able to predict some influential variables and take their effects into account in design. This study was performed to establish the effects of the number of bolts and bolt gage distance on the stiffness and strength of a double-angle connection under tension. Six experimental tests were conducted to describe the effects of these variables by comparing load-displacement relationship curves. In addition, two prediction models were proposed to estimate the initial stiffness and the maximum allowable tensile load based on the results of experimental tests. In the development of these prediction models, the effect of prying action was considered.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.228-229
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• 2009

탐침현미경(Atomic Force Microscope)을 이용하여 탐침과 표면사이에 나노스케일의 접촉 반경을 가지는 접촉보를 만든 후 접촉 강성(contact stiffness) 을 관찰하였다. 다양한 습도 조건하에서 접촉 강성의 변화를 측정한 결과, 습도에 의해 접촉부의 인장 거동이 달라짐을 확인할 수 있었으며, 습도 변화에 따라 인장 거동의 천이점이 존재함을 확인할 수 있었다.