• Title/Summary/Keyword: Uniaxial compression test

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Failure Behavior of High Strength Concrete under Uniaxial and Biaxial Compression (고강도 콘크리트의 일축 및 이축 압축하의 파괴거동)

  • Lee, Sang-Kuen;Song, Young-Chul
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.6 no.1
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    • pp.223-231
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    • 2002
  • The pilot tests for the development of biaxial failure envelope of high strength concrete of reactor containments were performed. To apply biaxial loads to concrete, the plate specimens were used. The technical difficulties encountered on the development of a suitable biaxial test setup were discussed. To decide the optimum thickness of plate specimen, the nonlinear finite element analyses using ABAQUS were performed for a 1/8 model of cylindrical specimen(${\Phi}150{\times}300$) and four 1/4 models of plate Specimens ($200{\times}200{\times}T$(=30, 50, 60, 70)mm) under uniaxial compression. Analytical values and test data of relative strength ratio between those specimens with different geometric shapes were also compared. The various test data were obtained under uniaxial compression, uniaxial tension, and biaxial compression and then the stress-strain responses were plotted. The test data indicated that the strength of concrete under biaxial compression, $f_1/f_2=-1/-1$, is 15 percent larger than that under uniaxial compression and the poisson's ratio of concrete is 0.16. Teflon pads employed to eliminate friction between test specimen and loading platens showed an excellent effect under biaxial compression.

Laboratory experiment on the assessment of the ground strength with corestone (실내실험을 통한 핵석지반의 강도정수 산정연구)

  • 이수곤;김동은;황의성
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.03a
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    • pp.95-102
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    • 2003
  • Corestone rock mass has complex characters because it is made up of stronger and stiffer corestone in a weaker and softer matrix. Physical model corestone rock mass made up of stiffer corestone in weaker matrix were tested in uniaxial compression and numercal modelling analysis The result of the uniaxial compression tests showed that increasing the corestone proportion generally increased the modulus of deformation. And the strength decreased in the lower corestone proportion, but it increased in the higher proportion(45%, 65% corestone by volume). The strength and the modulus of deformation were not affected by different size coretone on the same proportion. The result of the numerical modelling analysis showed similar trend compared with the result of the result of the uniaxial compression test. But though the result of th uniaxial compression test is similar to the result of the numerical modelling analysis, it's unreasonalble to apply the results of this paper to in situ corestone rock mass. So mere laboratory tests including triaxial test and the other numerical program analyses are necessary to apply the results to in situ corestone mass

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Estimation of rock tensile and compressive moduli with Brazilian disc test

  • Wei, Jiong;Niu, Leilei;Song, Jae-Joon;Xie, Linmao
    • Geomechanics and Engineering
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    • v.19 no.4
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    • pp.353-360
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    • 2019
  • The elastic modulus is an important parameter to characterize the property of rock. It is common knowledge that the strengths of rocks are significantly different under tension and compression. However, little attention has been paid to the bi-modularity of rock. To validate whether the rock elastic moduli in tension and compression are the same, Brazilian disc, direct tension and compression tests were conducted. A horizontal laser displacement meter and a pair of vertical and transverse strain gauges were applied. Four types of materials were tested, including three types of rock materials and one type of steel material. A comprehensive comparison of the elastic moduli based on different experimental results was presented, and a tension-compression anisotropy model was proposed to explain the experimental results. The results from this study indicate that the rock elastic modulus is different under tension and compression. The ratio of the rock elastic moduli under compression and tension ranges from 2 to 4. The rock tensile moduli from the strain data and displacement data are approximate. The elastic moduli from the Brazilian disc test are consistent with those from the uniaxial tension and compression tests. The Brazilian disc test is a convenient method for estimating the tensile and compressive moduli of rock materials.

A Study on the Equi-biaxial Tension Test of Rubber Material (고무재료의 등 이축 인장시험에 관한 연구)

  • 김완두;김동진;김완수;이영신
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.5
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    • pp.95-104
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    • 2003
  • The material properties of rubber was determined by the experiments of uniaxial tension, uniaxial compression, planer tension, equi-biaxial tension and volumetric compression. In compression test, it is difficult to obtain the pure state of compression stress and strain due to friction force between the specimen and compression platen. In this study, the stress and strain data from the equi-biaxial tension test were converted to compression stress and strain and compared to a pure state of simple compression data when friction was zero. The compression test device with the tapered platen was proposed to overcome the effect of friction. It was fumed out that the relationship of the stress and strain using the tapered platen was in close agreement with the pure compressive state.

A study on critical strain properties of intact rock due to Petrogenesis (암석의 성인별 한계변형률 특성에 관한 연구)

  • Kim, Young-Su;Park, Si-Hyun;Kim, Dae-Man;Shin, Ji-Seop;Han, Hee-Su
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.1133-1138
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    • 2009
  • This study was conducted in order to know the internal application of the critical strain graph. To evaluate critical strain graph, we carried out an uniaxial compression test with some of internal rocks: sandstone, shale, weathered granite, and pink granitic. Based on the uniaxial compression test, we deduced relations among critical strain, failure strain, uniaxial compression strength and modulus of elasticity. As a result, the study has found out the rocks, which have been tested, can be possibly evaluated by critical strain graph.

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A Study on the Equi-biaxial Tension Test of Rubber Material (고무재료의 이축 인장시험에 관한 연구)

  • Kim, Dong-Jin;Kim, Wan-Doo;Kim, Wan-Soo;Lee, Young-Shin
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.425-430
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    • 2003
  • The material properties of rubber was determined by the experiments of uniaxial tension, uniaxial compression, planer tension, equi-biaxial tension and volumetric compression. In compression test, it is difficult to obtain the pure state of compression stress and strain due to friction force between the specimen and compression platen. In this study, the stress and strain data from the equi-biaxial tension test were converted to compression stress and strain and compared to a perfect state of simple compression data when friction was zero. The compression test device with the tapered platen was proposed to overcome the effect of friction. It was turned out that the relationship of the stress and strain using the tapered platen was in close agreement with the pure compressive state.

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Stress corrosion index of Kumamoto andesite estimated from two types of testing method

  • Jeong Hae-Sik;Nara Yoshitaka;Obara Yuzo;Kaneko Katsuhiko
    • 한국지구물리탐사학회:학술대회논문집
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    • 2003.11a
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    • pp.221-228
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    • 2003
  • The stress corrosion index of Kumamoto andesite are evaluated by two types of testing method. One is the uniaxial compression test under various water vapor pressures, and the other is the double torsion (DT) test under a constant water vapor pressure. For the uniaxial compression tests, the uniaxial compressive strength increases linearly with decreasing water vapor pressure on the double logarithmic coordinates. As the results, the stress corrosion index obtained is estimated 44. On the other hand, in the DT test, the relaxation (RLX) test and the constant displacement rate (CDR) test were conducted. For the CDR test, as the displacement rate of loading point increases, the crack velocity increases. However, the fracture toughness is constant regardless of the change in displacement rate and the average fracture toughness is evaluated $2.07MN/m^{3/2}$. For the RLX test, the crack velocity-stress intensity factor curves are smooth and linear. The stress corrosion index estimated from the curves is 37. Comparing stress corrosion indexes in the uniaxial compression test and the DT test, there is no significant difference in these values, and they are considered to be in coincident each other regardless of testing methods. Therefore, it is concluded that stress corrosion is one of material constants of rock.

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Behavior of Plain and Steel Fiber Reinforced High Strengh Concrete Under Uniaxial and Biaxial Compression (1축 및 2축 압축을 받는 고강도콘크리트 및 강섬유보강 고강도콘크리트의 거동)

  • Lim, Dong-Hwan;Park, Sung-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.5-8
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    • 2005
  • The purpose of this study is to investigate the mechanical characteristics of plain and steel fiber high strength concrete under uniaxial and biaxial loading condition. A number of plain and steel fiber high strength concrete cubes having 28 days compressive strength of 82.7Mpa (12,000psi) were made and tested. Four principal compression stress ratios, and four fiber concentrations were selected as major test variables. From test results, it is shown that confinement stress in minor stress direction has pronounced effect on the strength and deformational behavior. Both of the stiffness and ultimate strength of the plain and fiber high strength concrete increased. The maximum increase of ultimate strength occurred at biaxial stress ratio of 0.5 in the plain high strength concrete and the value were recorded 30 percent over than the strength under uniaxial condition. The failure modes of plain high strength concrete under uniaxial compression were shown as splitting type of failure but steel fiber concrete specimens under biaxial condition showed shear type failure.

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Finite Element Modeling of Low Density Polyurethane Foam Material (저밀도 폴리우레탄 포옴재료의 유한요소 모델링)

  • 김원택;최형연
    • Transactions of the Korean Society of Automotive Engineers
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    • v.4 no.2
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    • pp.183-188
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    • 1996
  • The compressive stress-strain response of Low Density Polyurethane foam material is modeled using the finite element method. A constitutive equation which include experimental constants based on quasi-static and dynamic uniaxial compression test is proposed. Impact test with different impactor masses and velocities are performed to verify the proposed model. The comparison between impact test and finite element analysis shows good agreements.

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Evaluation of Flow Stress of Metal up to High Strain (금속소재의 고변형률 영역 유동응력선도 평가)

  • Lee, S.K.;Lee, I.K.;Lee, S.Y.;Lee, S.M.;Jeong, M.S.
    • Transactions of Materials Processing
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    • v.29 no.6
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    • pp.316-322
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    • 2020
  • The flow stress curve is usually determined via uniaxial tensile or simple compression test. However, the flow stress curve up to high strain cannot be obtained using these two tests. This study presents a simple method for obtaining the flow stress curve up to high strain via FE analysis, a simple compression test, and an indentation test. In order to draw the flow stress curve up to high strain, the indentation test was carried out with the pre-stained specimen using the simple compression test. The flow stress curve of Al6110 was evaluated up to high strain using the proposed method, and the result was compared with the flow stress curve of the uniaxial tensile test of the initial material.