• Title/Summary/Keyword: Material similitude

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Similitude Law An Equivalent Three Phase Similitude Law for Pseudodynamic Test on Small-scale Reinforced Concrete Structures (철근콘크리트 구조물의 유사동적실험을 위한 Equivalent Three Phase Similitude LaW)

  • ;;;Guo, Xun
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.09a
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    • pp.303-310
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    • 2003
  • Small-scale models have been frequently used for experimental evaluation of seismic performance because of limited testing facilities and economic reasons. However, there are not enough studies on similitude law for analogizing prototype structures accurately with small-scale models, although conventional similitude law based on geometry is not well consistent in the inelastic seismic behavior. When fabricating prototype and small-scale model of reinforced concrete structures by using the same material, added mass is demanded from a volumetric change and scale factor could be limited due to size of aggregate. Therefore, it is desirable that different material is used for small-scale models. Thus, a modified similitude law could be derived depending on geometric scale factor and equivalent modulus ratio. In this study, compressive strength tests are conducted to analyze equivalent modulus ratio of micro-concrete to normal-concrete. Equivalent modulus ratios are divided into elastic, weak nonlinear and strong nonlinear phases, which are based on ultimate strain level. Therefore, an algorithm adaptable to the pseudodynamic test, considering equivalent three phase similitude law based on seismic damage levels, is developed. In addition, prior to tile experiment, it is verified numerically if tile algorithm is applicable to the pseudodynamic test.

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A Study on the Similitude of Material for Small-Scale Model Mix Proportion of Concrete Pavement. (콘크리트 포장 축소모델 배합의 재료적 상사성에 관한 연구)

  • 배주성;고영주;김재경;김평수
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.10a
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    • pp.103-110
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    • 1997
  • The objective of this study is to provide the information on the small-scale model mix proportion when the behavior of prototype concrete pavement is studied through small-scale model experiments. However it is difficult to obtain a model material to simulate the prototype concrete by scaling the individual components according to the laws of similitude. In this paper, the stress-strain behavior in uniaxial compression is used as a means to correlate materials similitude between the prototype and the model concrete. Based on th results of experiments, We compared the stress-strain curves of prototype and model concrete mixes using a nondimensional basis. In order to simulate the stress-strain curves of prototype concrete, it is important that various mix as of model concrete selected properly which are varied from aggregate grading, cement-aggregate and sand-aggregate ratio.

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Scaling laws for vibration response of anti-symmetrically laminated plates

  • Singhatanadgid, Pairod;Ungbhakorn, Variddhi
    • Structural Engineering and Mechanics
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    • v.14 no.3
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    • pp.345-364
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    • 2002
  • The scaling laws for vibration response of anti-symmetrically laminated plates are derived by applying the similitude transformation to the governing differential equations directly. With this approach, a closed-form solution of the governing equations is not required. This is a significant advantage over the method employed by other researchers where similitude transformation is applied to the closed-form solution. The scaling laws are tested by comparing the similitude fundamental frequencies to the theoretical fundamental frequencies determined from the available closed-form solutions. In case of complete similitude, similitude solutions from the scaling laws exactly agree with the theoretical solutions. Sometimes, it may not be feasible to select the model which obeys the similarity requirement completely, therefore partial similitude is theoretically investigated and approximate scaling laws are recommended. The distorted models in stacking sequences and laminated material properties demonstrate reasonable accuracy. On the contrary, a model with distortion in fiber angle is not recommended. The derived scaling laws are very useful to determine the vibration response of complex prototypes by performing the experiment on a model with required similarities.

Experimental Study on the Similitude in Flexure, Shear and Bond Behavior of Small-scale R.C. Beams (축소모델 철근콘크리트 보의 휨, 전단 및 정착거동에 관한 상사성 실험연구)

  • 이한선;고동우
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10a
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    • pp.547-552
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    • 1998
  • The small-scale models have been utilized for the prediction of inelastic behavior of reinforced concrete structures for a long time. The parameters that affect the similitude between the model and the prototype are various. Among them, the effect of bond between the model reinforcement and the model concrete is one of the most important factors. The study reported herein is addressed to verifying this similitude in bond behavior. Another topic is the similitude in shear. The selected scales are 1/1, 1/5, 1/10 and 1/12. Two prototype specimens and three models were tested in addition to the associated material tests. The test results are compared from the viewpoint of similitude.

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Similitude in Flexural Bond Behavior of Small-Scale Reinforced Concrete Beams (축소모델 철근콘크리트 보의 휨부착거동에 있어서의 상사성)

  • 이한선;고동우
    • Journal of the Korea Concrete Institute
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    • v.11 no.3
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    • pp.47-57
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    • 1999
  • The small-scale models have been utilized for the prediction of inelastic behavior of reinforced concrete structures for several decades. The parameters that affect the similitude between the model and prototype are various. Among them, the effect of bond between the model reinforcement and the model concrete is one of the most important factors. The study reported herein is addressed to verifying this similitude in bond behavior. The simple beams which have the lap splice at the midspan were made and flexural tests were performed under two-point loading. The length of lap splice are varied from 0.4ld through 0.7ld and up to 1.0ld where ld is the development length of the reinforcement. The selected scales are 1/1, 1/5, 1/10 and 1/12. Two prototype specimens and three models were tested in addition to the associated material tests and the test results are compared from the viewpoint of similitude.

An Equivalent Multi-Phase Similitude Law for Pseudodynamic Test on Small-scale RC Models : Verification Tests (RC 축소모형의 유사동적실험을 위한 Equivalent Multi-Phase Similitude Law : 검증실험)

  • Kim, Nam-Sik;Lee, Ji-Ho;Chang, Sung-Pil
    • Journal of the Earthquake Engineering Society of Korea
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    • v.8 no.5 s.39
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    • pp.35-43
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    • 2004
  • Small-scale models have been frequently used for seismic performance tests because of limited testing facilities and economic reasons. However, there are not enough studies on similitude law for analogizing prototype structures accurately with small-scale models, although conventional similitude law based on geometry is not well consistent in the inelastic seismic behavior. When fabricating prototype and small-scale model of reinforced concrete structures by using the same material, added mass is demanded from a volumetric change and scale factor could be limited due to aggregate size. Therefore, it is desirable that different material is used for small-scale models. Thus, a modified similitude law could be derived depending on geometric scale factor, equivalent modulus ratio and ultimate strain ratio. In this study, compressive strength tests are conducted to analyze the equivalent modulus ratio of micro-concrete to normal-concrete. Then, equivalent modulus ratios are divided into multi-phase damage levels, which are basically dependent on ultimate strain level. Therefore, an algorithm adaptable to the pseudodynamic test, considering equivalent multi-phase similitude law based on seismic damage levels, is developed. Test specimens, consisted of prototype structures and 1/5 scaled models as a reinforced concrete column, were designed and fabricated based on the equivalent modulus ratios already defined. Finally quasistatic and pseudodynamic tests on the specimens are carried out using constant and variable modulus ratios, and correlation between prototype and small-scale model is investigated based on their test results. It is confirmed that the equivalent multi-phase similitude law proposed in this study could be suitable for seismic performance tests on small-scale models.

The Similitude of Material for Small-Scale Model Mix Proportion of Concrete Pavement (시멘트콘크리트 포장체의 거동연구를 위한 축소모델 배합의 재료적 상사성)

  • Ko, Young-Zoo;Lee, Yeoung-Woo;Bae, Ju-Seong
    • Magazine of the Korea Concrete Institute
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    • v.11 no.2
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    • pp.139-145
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    • 1999
  • The objective of this study is to provide the information on the small-scale model mix proportion when the behavior of prototype concrete pavement is studied through small-scale model experiments. However it is difficult to obtain a model material to simulate the prototype concrete by scaling the individual components according to the laws of similitude. In this paper, the stress-strain behavior in uniaxial compression is used as a means to correlate material similitude between the prototype and the model concrete. Based on the results of experiments, we compared the stress-strain curves of prototype and model concrete mixes using a nondimensional basis. In order to simulate the stress-stain curves of prototype concrete, it is important that various mix proportions of model concrete selected properly which are varied from aggregate grading, cement-aggregate and sand-aggregate ratio.

A Study on Similitude Law for Pseudodynamic Tests and Shaking Table Tests on Small-scale R/C Models (철근콘크리트 축소모형의 유사동적실험과 진동대 실험을 위한 상사법칙 연구)

  • Yang, Hui-Gwan;Seo, Ju-Won;Cho, Nam-So;Chang, Sung-Pil
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.545-552
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    • 2006
  • Small-scale models have been frequently used for seismic performance tests because of limited testing facilities and economic reasons. However, there are not also enough studies on similitude law for analogizing prototype structures accurately with small-scale models, although conventional similitude law based on geometry similitude is not well consistent in their inelastic seismic behaviors. When fabricating prototype and small-scale model of reinforced concrete structures by using the same material, added mass is demanded from a volumetric change and scale factor could be limited due to aggregate size. Therefore, it is desirable to use different materials for small-scale model. In our recent study, a modified similitude law was derived depending on geometric scale factor, equivalent modulus ratio and ultimate strain ratio. And quasi-static and pseudo-dynamic tests on the specimens are carried out using constant and variable modulus ratios, and correlation between prototype and small-scale model is investigated based on their test results. In this study, tests on scaled model of different concrete compressive strength aye carried out. In shaking table tests, added mass can not be varied. Thus, constant added mass on expected maximum displacement was applied and the validity was verified in shaking table tests. And shaking table tests on non-artificial mass model is carried out to settle a limitation of acceleration and the validity was verified in shanking table tests.

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An Equivalent Multi-Phase Similitude Law for Pseudodynamic Test on Small-scale RC Models (RC 축소모형의 유사동적실험을 위한 Equivalent Multi-Phase Similitude Law)

  • ;;;Guo, Xun
    • Journal of the Earthquake Engineering Society of Korea
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    • v.7 no.6
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    • pp.101-108
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    • 2003
  • Small-scale models have been frequently used for experimental evaluation of seismic performance because of limited testing facilities and economic reasons. However, there are not enough studies on similitude law for analogizing prototype structures accurately with small-scale models, although conventional similitude law based on geometry is not well consistent in the inelastic seismic behavior. When fabricating prototype and small-scale model of reinforced concrete structures by using the same material. added mass is demanded from a volumetric change and scale factor could be limited due to size of aggregate. Therefore, it is desirable that different material is used for small-scale models. Thus, a modified similitude law could be derived depending on geometric scale factor and equivalent modulus ratio. In this study, compressive strength tests are conducted to analyze equivalent modulus ratio of micro-concrete to normal-concrete. Equivalent modulus ratios are divided into multi phases, which are based on ultimate strain level. Therefore, an algorithm adaptable to the pseudodynamic test. considering equivalent multi-phase similitude law based on seismic damage levels, is developed. In addition, prior to the experiment. it is verified numerically if the algorithm is applicable to the pseudodynamic test.

Similitude Law on Material Non-linearity for Seismic Performance Evaluation of RC columns (RC기둥의 내진성능평가를 위한 재료비선형 상사법칙)

  • Lee, Do-Keun;Oh, Jung-Hwan;Cho, Jae-Yeol
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.119-120
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    • 2010
  • Recently, for evaluate seismic performance, pseudo-dynamic test and shaking table test are experimented through using small scaled model to relief restriction, though, reserch about similitude law are insufficient. In this study, propose adequate similitude law for improve economical efficiency and reliability.

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