• Title/Summary/Keyword: strain plane

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Investigations on the bearing strength of stainless steel bolted plates under in-plane tension

  • Kiymaz, G.
    • Steel and Composite Structures
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    • v.9 no.2
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    • pp.173-189
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    • 2009
  • This paper presents a study on the behavior and design of bolted stainless steel plates under in-plane tension. Using an experimentally validated finite element (FE) program strength of stainless steel bolted plates under tension is examined with an emphasis on plate bearing mode of failure. A numerical parametric study was carried out which includes examining the behavior of stainless steel plate models with various proportions, bolt locations and in two different material grades. The models were designed to fail particularly in bolt tear-out and material piling-up modes. In the numerical simulation of the models, non-linear stress-strain material behavior of stainless steel was considered by using expressions which represent the full range of strains up to the ultimate tensile strain. Using the results of the parametric study, the effect of variations in bolt positions, such as end and edge distance and bolt pitch distance on bearing resistance of stainless steel bolted plates under in-plane tension has been investigated. Finally, the results obtained are critically examined using design estimations of the currently available international design guidance.

A return mapping algorithm for plane stress and degenerated shell plasticity

  • Liu, Z.;Al-Bermani, F.G.A.
    • Structural Engineering and Mechanics
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    • v.3 no.2
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    • pp.185-192
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    • 1995
  • A numerical algorithm for plane stress and shell elasto-plasticity is presented in this paper. The proposed strain decomposition (SD) algorithm is an elastic predictor/plastic corrector algorithm, and in the context of operator splitting, is a return mapping algorithm. However, it differs significantly from other return mapping algorithms in that only the necessary response functions are used without invoking their gradients, and the stress increment is updated only at the end of the time step. This makes the proposed SD algorithm more suitable for materials with complex yield surfaces and will guard against error accumulation during the time step. Comparative analyses of structural systems using the proposed strain decomposition (SD) algorithm and the iterative radial return (IRR) algorithm are presented. The results demonstrate the accuracy and usefulness of the proposed algorithm.

Vibration and Damping Analysis of Cross-ply Plate Strip Including Layer-wise In-plane Displacements (면내 변위의 변화를 고려한 Cross-ply 적층판의 진동 및 감쇠해석)

  • Koo, Kyo-Nam;Lee, in
    • Journal of KSNVE
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    • v.2 no.4
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    • pp.305-315
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    • 1992
  • In order to investigate the effects of layer-wise in-plane displacements on vibration and damping characteristics of composite laminated plates, the finite element method based on the generalized laminated plate theory(GLPT) has been formulated. Specific damping capacity of each mode was obtained by modal strain energy method. To see the effect of transverse shear on deformation, the strain energy of stress components was computed. The accuracy of this study was examined for the cylindrical bending vibration of cross-ply plate strip. The results were very accurate compared with 3-D solutions. The numerical results show that through-thickness variation of in-plane displacements has not so much influence on the natural frequency, but has a great influence on the damping of composite plates, especially on the damping of thick composite plates since the damping is affected by local behavior while the natural frequency is affected by global behavior.

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A Study on the Angle of Localization of a Metal Specimen under Uniaxial Tension with Plane Strain Condition (평면 변형 조건에서 일축 인장력을 받는 금속 재료의 불연속 변위 각에 대한 연구)

  • Park, Jae-Gyun;Kim, Mi-Rim
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.3
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    • pp.275-281
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    • 2011
  • When a flat bar type metal specimen for general tension test is subject to incremental uniaxial tension, a narrow plastic shear band, so called luders band, is generated at some instance. This band typically has an angle to the axis of specimen and many early researches have been done to investigate the condition and angle of this localized deformation phenomenon by many researchers. This study follows the procedure of Thomas(1961) under plane stress boundary condition. $J_2$ plasticity theory, balance of linear momentum, and constitutive equations are used to derive the angle of luders band under plain strain boundary condition. The result was confirmed by other angle based on acoustic tensor theory.

Crack constitutive model for the prediction of punching failure modes of fiber reinforced concrete laminar structures

  • Ventura-Gouveia, A.;Barros, Joaquim A.O.;Azevedo, Alvaro F.M.
    • Computers and Concrete
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    • v.8 no.6
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    • pp.735-755
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    • 2011
  • The capability of a multi-directional fixed smeared crack constitutive model to simulate the flexural/punching failure modes of fiber reinforced concrete (FRC) laminar structures is discussed. The constitutive model is implemented in a computer program based on the finite element method, where the FRC laminar structures were simulated according to the Reissner-Mindlin shell theory. The shell is discretized into layers for the simulation of the membrane, bending and out-of-plane shear nonlinear behavior. A stress-strain softening diagram is proposed to reproduce, after crack initiation, the evolution of the normal crack component. The in-plane shear crack component is obtained using the concept of shear retention factor, defined by a crack-strain dependent law. To capture the punching failure mode, a softening diagram is proposed to simulate the decrease of the out-of-plane shear stress components with the increase of the corresponding shear strain components, after crack initiation. With this relatively simple approach, accurate predictions of the behavior of FRC structures failing in bending and in shear can be obtained. To assess the predictive performance of the model, a punching experimental test of a module of a façade panel fabricated with steel fiber reinforced self-compacting concrete is numerically simulated. The influence of some parameters defining the softening diagrams is discussed.

Earth Pressure Acting on the Diaphragm Wall of a Shaft in Cohesionless Soils (사질토지반에 설치된 원형수직구의 강성흙막이벽에 작용하는 토압)

  • Chun, Byung-Sik;Shin, Young-Wan;Kong, Jin-Young;Hwang, Yi-Sung
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.03a
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    • pp.734-741
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    • 2008
  • At-rest and active earth pressure in plane strain condition have been applied to the design of cylindrical retaining walls. But many researchers have indicated that the earth pressure on the cylindrical retaining walls would be smaller than in plane strain condition due to wall deformation and stress relief. In this paper, the distribution of earth pressure acting on diaphragm wall of a shaft in dry sand was predicted by using the convergence confinement method and model test was performed to verify the estimated values. Test results showed that the earth pressure acting on the diaphragm wall of a shaft was expected to be 1.1~1.5 times larger than active earth pressure of plane strain condition and 0.7~0.9 times less than at-rest earth pressure.

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Measurement of Inward Turbulent Flows Subject to Plane Rate of Strain in a Rotating 90 Deg. Curved Duct of Variable Cross-Section (단순변형율 조건 하의 회전하는 가변단면 $90^{\circ}$ 곡덕트 내 내향 난류유동 측정)

  • Kim, Dong-Chul;Choi, Young-Don
    • Proceedings of the KSME Conference
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    • 2000.04b
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    • pp.765-770
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    • 2000
  • Hot-wire measurements are reported on the developing turbulent flows subject to plane rate of strain in a rotating $90^{\circ}$ dog bend. The cross-section of the bend varies from $100mm{\times}50mm$ rectangular shape at the bend inlet gradually to the $50mm{\times}100mm$ shape at the bend outlet with remaining a constant area. Data signals from the rotating test section are transmitted through a slip ring to the personal computer which is located at the outside of the rotating disc. 3-dimensional velocity and 6 Reynolds stress components were calculated from the equations which correlate the fluctuating and mean voltage values measured with rotating a slant type hot-wire into 6 orientations. The effects of Coriolis and centrifugal forces on the mean motions and turbulence structures are investigated with respect to rotational speed.

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A STUDY ON THE FRACTURE TOUGHNESS OF DENTAL AMALGAMS (치과용(齒科用) 아말감의 파괴인성(破壞靭性)에 관한 연구(硏究))

  • Huh, Hyeon-Do;Kim, Yung-Hai
    • Restorative Dentistry and Endodontics
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    • v.15 no.1
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    • pp.20-32
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    • 1990
  • The plane strain fracture toughness of a material characterize the resistance to fracture in the presence of a sharp crack under severe tensile condition. Fracture toughness can be determined by indentation method. The purpose of this study was to investigate the fracture toughness of dental amalgams by measuring the plane strain fracture toughness and the fracture toughness from indentation method. Two conventional and four high copper amalgam alloys were employed for this study. The amalgams were prepared according to the A.D.A. spec. No. 1 and inserted into the specially designed mould with the single edge notch specimen to use in 3-point bending method. The specimens (20mm long, 4mm wide, 2mm thick) were stored at $37^{\circ}C$ for 1 week, and tested in 3-point bending by means of Instron at a cross-head speed of 1mm/min. In indentation method, the specimens were made in same manner as single edge notch specimens. The test was conducted with Vickers hardness tester at 10kg load. The following results were obtained. 1. The plane strain fracture toughness and the fracture toughness from indentation method were higher in the low copper amalgams than the high copper amalgams. 2. In high copper amalgams, the fracture toughness of amalgams decreases according as the copper contents increase. 3. In similar copper contents, the single composition amalgams have a higher fracture toughness than the admixed amalgams.

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Plane strain consolidation of a compressible clay stratum by surface loads

  • Rani, Sunita;Puri, Manoj;Singh, Sarva Jit
    • Geomechanics and Engineering
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    • v.7 no.4
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    • pp.355-374
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    • 2014
  • An analytical solution of the fully coupled system of equations governing the plane strain deformation of a poroelastic medium with anisotropic permeability and compressible fluid and solid constituents is obtained. This solution is used to study the consolidation of a poroelastic clay layer with free permeable surface resting on a rough-rigid permeable or impermeable base. The stresses and the pore pressure are taken as the basic state variables. Displacements are obtained by integrating the coupled constitutive relations. The case of normal surface loading is discussed in detail. The solution is obtained in the Laplace-Fourier domain. Two integrations are required to obtain the solution in the space-time domain which are evaluated numerically for normal strip loading. Consolidation of the clay layer and diffusion of pore pressure is studied for both the bases. It is found that the time settlement is accelerated by the permeability of the base. Initially, the pore pressure is not affected by the permeability of the base, but has a significant effect, as we move towards the bottom of the layer. Also, anisotropy in permeability and compressibilities of constituents of the poroelastic medium have a significant effect on the consolidation of the clay layer.

Measurement of Outward Turbulent Flows Subject to Plane Rate of Strain in a Rotating 90 Deg. Curved Duct of Variable Cross-Section (단순변형률 조건 하의 회전하는 가변단면 $90^{\circ}$ 곡덕트내 외향 난류유동 측정)

  • Oh, Chang-Min;Choi, Young-Don
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.24 no.5
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    • pp.623-631
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    • 2000
  • Hot-wire measurements were carried out on the developing turbulent flows subject to plane rate of strain in a rotating curved duct. The cross-section of the curved duct varies from 100mm${\times}$50mm rectangular shape at the bend inlet gradually to the 50mm${\times}$100mm rectangular shape at the bend outlet. Experimental setup consists of the test section of $90^{\circ}$ curved duct, rotating disc of 1.95m diameter, Ag-Ni precision slip ring, automatic traversing mechanism, variable speed motor, centrifugal blower, orifice flowmeter and hot-wire anemometer. Data signals from the rotating curved duct are transmitted through the slip ring to the computer which is located at the outside of the rotating disc. 3-dimensional velocity and 6 Reynold stresses components were obtained from the fluctuating and mean voltage measured by the slant type hot-wire probe rotating into 6 orientations. We investigate the effects of Coriolis and centrifugal forces on the turbulence structure.