• Title/Summary/Keyword: axial tension test

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An Experimental Study on the Fatigue Behavior of Torque Shear Type High Tension Bolted Joints (Torque Shear형 고장력 볼트 이음부의 피로거동에 관한 실험적 연구)

  • CHANG, Dong Il;Lee, Sung Uk
    • Journal of Korean Society of Steel Construction
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    • v.8 no.3 s.28
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    • pp.151-160
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    • 1996
  • The fatigue test under the constant amplitude repeated loading is performed to investigate the fatigue behavior of the Torque Shear type high tension bolted joint which is able to manage the axial force uniformly. From the test results, it's known that the reduction of the axial force of T/S bolt followed by the elasped time is similar to that of the high tension bolts. The difference of relaxation is not occurred according to the position of bolts, the size of the introduced axial force but the effect of the variation of temperature is large. In the reduction of the axial force followed by the cumulation of the fatigue load, the outer bolt is larger than the inner bolt. This result depends on the difference in the distribution of the non-slip zone. The variation of the surface roughness affects the slip and the reduction of the anal force.

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A Study on Fracture Characteristics of Chemically Prestressed Mortar (화학적 프리스트레스가 도입된 모르타르의 파괴특성에 관한 연구)

  • 안중길;심별;송하원;변근주
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.828-833
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    • 2003
  • In this paper, a study on fracture characteristics of chemically prestressed mortar with addition of expansive additives was carried out. Uni-axial tension tests with reinforced mortar specimen restrained by embedded reinforcing bar and three point bending tests with notched steel fiber reinforced beams were carried out to verify the characteristics of the cracking behavior, the tension stiffening effect due to bond between rebar and mortar, and fracture characteristic. Tension stiffening curve for the chemically prestressed mortar was obtained from uni-axial tension test. And increased fracture energy due to the chemical prestress was also obtained from bending test and tension softening curve for chemically prestressed mortar was also obtained.

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Stress Analysis on Composite Cylindrical Shells with a Reinforced Cutout Subjected to Axial Load (보강 개구부가 있는 복합재료 원통셸의 축방향 하중에 따른 응력해석)

  • 이영신;류충현;김영완
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 1999.11a
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    • pp.211-214
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    • 1999
  • The stress distribution around the cutout of composite cylindrical shells with a circular or elliptical reinforced cutout subjected to axial compression or tension is studied by asymptotic method. Analytical solutions used a Donnell type orthotropic shell theory are presented by the defined stress concentration factor and are compared to experimental results. The experiment used the universal testing machine (UTM), strain gage and fixtures designed/manufactured for axial tension test of a cylindrical shell is carried and the composite material used in the experiment is plain weave glass fiber reinforced plastic (GFRP).

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Shear behavior of exposed column base connections

  • Cui, Yao
    • Steel and Composite Structures
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    • v.21 no.2
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    • pp.357-371
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    • 2016
  • Column base connections are critical components in steel structures because they transfer axial forces, shear forces and moments to the foundation. Exposed column bases are quite commonly used in low- to medium-rise buildings. To investigate shear transfer in exposed column base plates, four large scale specimens were subjected to a combination of axial load (compression or tension) and lateral shear deformations. The main parameters examined experimentally include the number of anchor rod, arrangement of anchor rod, type of lateral loading, and axial force ratio. It is observed that the shear resisting mechanism of exposed column base changed as the axial force changed. When the axial force is in compression, the resisting mechanism is rotation type, and the shear force will be resisted by friction force between base plate and mortar layer. The specimens could sustain inelastic deformation with minimal strength deterioration up to column rotation angle of 3%. The moment resistance and energy dissipation will be increased as the number of anchor rods increased. Moreover, moment resistance could be further increased if the anchor rods were arranged in details. When the axial force is in tension, the resisting mechanism is slip type, and the shear force will be resisted by the anchor rods. And the shear resistance was reduced significantly when the axial force was changed from compression to tension. The test results indicated that the current design approach could estimate the moment resistance within reasonable acceptance, but overestimate the shear resistance of exposed column base.

FE Simulation of Axial Crushing Test for AZ31 Tube Considering Tension-Compression Asymmetry (압축-인장 비대칭을 고려한 AZ31 튜브의 압괴해석)

  • Yoon, Jong-Hun;Lee, Jung-Hwan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.9
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    • pp.997-1002
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    • 2012
  • With the increasing demand for lightweight materials to reduce fuel consumption, especially in the transportation industry, magnesium alloys are being widely studied. However, there are several limitations to the large-scale application of magnesium alloys in a structure because of their low formability and strong anisotropy. In order to take into account both the strong anisotropy and tension-compression asymmetry of AZ31 sheet alloy, the Cazacu-Plunkett-Barlat yield criterion (Cazacu, 2006) was adopted in material modeling. The variation of the anisotropic coefficients that describe the yield surface evolution of AZ31 is optimized using an interpolation function based on specific calibration results. It generates continuous yield surfaces, which makes it possible to describe different hardening rates in tension and compression as well as the tension-compression asymmetry of magnesium alloys. The performance of the CPB06 yield criterion for simulating an axial crushing test was tested and compared with that of the Hill (1948) yield criterion.

An Experimental Study on the Fatigue Behavior of T-Type Tension Joints with High Tension Bolt (고장력볼트 T-인장이음의 피로거동에 관한 실험적 연구)

  • Lee, Seung Yong;Choi, Jun Hyeok
    • Journal of Korean Society of Steel Construction
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    • v.28 no.6
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    • pp.459-465
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    • 2016
  • In this paper, it was performed the fatigue test to examine the effect of cyclic loading for the simple T-joint. Axial force of bolt by clamping and the change of the force by applied load were measured in the joint. And the bolt force, the failure mode and the fatigue strength under cyclic loading were investigated. The parameters of the tension joint were set to be the flange thickness and the diameter of bolt to a different stiffness of the joint in response to the combination. From the fatigue test, failure mode of tensile joints under cyclic loading could be evaluated using a static ultimate load of the specific failure mode in EC3. The fatigue strength of the tension joints was considerably higher than the fatigue strength of the EC3(36) that does not consider a lever action. However, the additional axial force by lever action occurs to an increase in the axial force of the bolt it requires a careful evaluation of the fatigue strength.

A Comparison Study for the Fatigue Behavior of H/T and T/S Bolt Friction Joint (H/T 와 T/S 볼트 마찰이음의 피로거동 비교·검토)

  • JUN, Je Sang;WOO, Sang Ik;LEE, Seong Heang;JUNG, Kyoung Sup
    • Journal of Korean Society of Steel Construction
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    • v.8 no.3 s.28
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    • pp.139-150
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    • 1996
  • H/T(High Tension) bolt is generally being used in joining the members of steel structure. It has some difficulties in management such as an adequate fastening force and a selection of proper instrument for fastening. T/S(Torque Shear Type High Tension) bolt which is more convenient and easier than H/T bolt in quality control has recently been developed. T/S bolts are produced and widely used these days in domestic, but those have not a detail regulation for their on. Those are only being used according to the specification for the H/T bolts. In this study, we tried to confirm the soundness of T/S bolts by the fatigue test of the modified specimens. First, we measured the reduction rate of the initial axial force with time at bolts. Second, we investigated the slip forces of bolts when the test specimen is loaded in tension. Third, we implemented the fatigue tests. During the test, we measured the variation of the axial forces of bolts under the cyclic loading. Finally, we compared and analyzed the fatigue behavior of H/T and T/S bolt, by S-N curve diagrams that are obtained in this study.

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Variation of Fatigue Properties in Nanoskinned Ti-6Al-4V - Rotating Bending and Axial Loading Tension-Compression Cycle - (Ti-6Al-4V 재의 UNSM 처리에 의한 피로특성변화 - 회전굽힘 피로시험과 축하중 인장압축 피로시험 비교 -)

  • Suh, Min-Soo;Pyoun, Young-Shik;Suh, Chang-Min
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.4
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    • pp.443-449
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    • 2012
  • Nanoskins were fabricated on a Ti-6Al-4V material by carrying out various surface treatments, i.e., deep rolling, laser shot peening, and ultrasonic nanocrystal surface modification (UNSM). These surface treatments are newly developed techniques and are becoming more popular for industrial applications. Fatigue tests were carried out using material test system (MTS); these tests included the axial loading tension-compression fatigue test (R = -1, RT, 5 Hz, sinusoidal wave) and rotating bending fatigue test (R = -1, RT, 3200 rpm). The analysis of the crack initiation pattern in the UNSM-treated material indicated that the crack was interior originating in the axial loading tension-compression cycle, and was surface originating in the bending fatigue test. UNSM treatment significantly improved the fatigue strength for the regime of above $10^6$ cycles that S-N curve of rotating bending stress clearly show the performance of a 5 mm titanium specimen after UNSM treatment is similar to that of an untreated 6 mm titanium specimen.

Characteristics Evaluation and Useful Life Prediction of Rubber Spring for Railway Vehicle (전동차용 방진고무스프링 특성평가 및 사용수명 예측)

  • Woo, Chang-Su;Park, Dong-Chul
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.104-111
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    • 2006
  • The non-linear properties of rubber material which are described as strain energy function are important parameter to design and evaluate of rubber spring. These are determined by material tests which are uni-axial tension and bi-axial tension. The computer simulation using the nonlinear element analysis program executed to predict and evaluate the load capacity and stiffness for chevron spring. In order to investigate the heat-aging effects on the rubber material properties, the acceleration test were carried out. Compression set results changes as the threshold are used for assessment of the useful life and time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. By using the compression set test, several useful life prediction for rubber material were proposed.

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Analysis of Failure Phenomena in Uni-axial Tension Tests of Friction Stir Welded AA6111-T4, AA5083-H18 and DP-Steel (마찰교반용접(FSW) 된 알루미늄 합금(AA6111-T4, AA5083-H18) 및 DP강 판재의 인장 실험시 파단 현상 해석)

  • Park, S.;Um, K.;Ma, N.;Ahn, K.;Chung, K.H.;Kim, Chong-Min;Okamoto, Kazutaka;Wagoner, R.H.;Chung, K.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2007.05a
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    • pp.258-261
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    • 2007
  • Failure phenomena in uni-axial tension test were experimentally and numerically investigated for AA6111-T4, AA5083-H18 and DP-Steel, which were friction-stir welded with the same and different thicknesses. Forming limit diagram(FLD) was measured using hemispherical dome stretching tests for base materials and also predicted by Hill's bifurcation and M-K theories for welded areas. Finite element simulations well predicted hardening behaviors, failure locations as well as failure patterns for the uni-axial tension tests especially utilizing very fine meshes and FLD along with stress softening.

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