• Title/Summary/Keyword: Transverse strain

Search Result 403, Processing Time 0.023 seconds

Investigation on the Experimental Results of Anisotropic Fracture Behavior for UHSS 1470 MPa Grade Sheets (초고강도 1470 MPa급 판재의 파단 이방성 실험 결과에 관한 연구)

  • J. Lee;H. J. Bong;D. Kim
    • Transactions of Materials Processing
    • /
    • v.32 no.2
    • /
    • pp.87-91
    • /
    • 2023
  • In the present work, the ductile fracture behaviors of ultra-high strength steel sheets along the different loading directions are investigated under various loading paths. Three loading paths, i.e., in-plane shear, uniaxial tension, plane strain tension deformations, are considered, and the corresponding specimens are described. The experiments are conducted using the digital image correlation (DIC) system to analyze the strain at the onset of the fracture. The experimental results show that the loading path for each specimen sample is linear, and different values of the fracture strains for the loading direction from the plane strain tension are observed. The ductile fracture model of the modified Mohr-Coulomb (MMC) is constructed based on the experimental data and evaluated along the rolling direction and transverse direction under various loading paths.

Evaluation of Shear Capacity According to Transverse Spacing of Wide Beam Shear Reinforced with Steel Plate with Openings (유공형 강판으로 전단보강된 넓은 보에서의 횡방향 보강 간격에 따른 전단성능 평가)

  • Choi, Jin Woong;Kim, Min Sook;Choi, Bong-Seob;Lee, Young Hak;Kim, Heecheul
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.28 no.3
    • /
    • pp.259-266
    • /
    • 2015
  • In this paper, transverse shear spacing and effective depth of wide beams were considered as parameters to evaluate the shear capacity of wide beam according to transverse spacing of steel plates with openings in experimental way. The eight specimens were composed of: five specimens of shear reinforced by steel plates with openings and three non-reinforced specimens. Crack, failure mode, strain and load-displacement curve of specimens were analysed. Shear contribution of shear reinforcement is evaluated and maximum transverse spacing of shear reinforcement was proposed. Shear strength of the specimen that reinforced with three stirrup legs was higher than shear strength of the specimen that reinforced with two stirrup legs. And as the effective depth increased, shear strength was increased.

Analysis of Seismic Response of the Buried Pipeline with Pipe End Conditions (I) (단부 경계조건을 고려한 매설관의 동적응답 해석 (I))

  • Jeong, Jin-Ho;Lee, Byong-Gil;Park, Byung-Ho
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2005.03a
    • /
    • pp.1148-1158
    • /
    • 2005
  • This work reports results of our study on the dynamic responses of the buried pipelines both along the axial and the transverse directions under various boundary end conditions. We have considered three cases, i.e., the free ends, the fixed ends, and the fixed-free ends. We have studied the seismic responses of the buried pipelines with the various boundary end conditions both along the axial and the transverse direction. We have considered three cases, i.e., the free ends, the fixed ends, and the fixed-free ends for the axial direction, and three more cases including the guided ends, the simply supported ends, and the supported-guided ends for the transverse direction. The buried pipelines are modeled as beams on elastic foundation while the seismic waves as a ground displacement in the form of a sinusoidal wave. The natural frequency and its mode, and the effect of parameters have been interpreted in terms of free vibration. The natural frequency varies most significantly by the soil stiffness and the length of the buried pipelines in the case of free vibration, which increases with increasing soil stiffness and decreases with increasing length of the buried pipeline. Such a behavior appears most prominently along the axial rather than the transverse direction of the buried pipelines. The resulting frequencies and the mode shapes obtained from the free vibration for the various boundary end conditions of the pipelines have been utilized to derive the mathematical formulae for the displacements and the strains along the axial direction, and the displacements and the bending strains along the transverse direction in case of the forced vibration. The negligibly small difference of 6.2% between our result and that of Ogawa et. al. (2001) for the axial strain with a one second period confirms the accuracy of our approach in this study.

  • PDF

Stress-Strain Behavior Characteristics of Concrete Cylinders Confined with FRP Wrap (FRP로 횡구속된 콘크리트의 응력-변형률 거동 특성)

  • Lee, Dae-Hyoung;Kim, Young-Sub;Chung, Young-Soo
    • Journal of the Korea Concrete Institute
    • /
    • v.19 no.2
    • /
    • pp.135-144
    • /
    • 2007
  • Recently, fiber-reinforced plastic(FRP) wraps are blown as an effective material for the enhancement and rehabilitation of aged concrete structures. The purpose of this investigation is to experimentally investigate behavior of concrete cylinder wrapped with FRP materials. Experimental parameters include compressive strength of concrete cylinder, FRP material, and confinement ratio. This paper presents the results of experimental studies on the performance of concrete cylinder specimens externally wrapped with aramid, carbon and glass fiber reinforced Polymer sheets. Test specimens were loaded in uniaxial compression. Axial load, axial and lateral strains were investigated to evaluate the stress-strain behavior, ultimate strength ultimate strain etc. Test results showed that the concrete strength and confinement ratio, defined as the ratio of transverse confinement stress and transverse strain were the most influential factors affecting the stress-strain behavior of confined concrete. More FRP layers showed the better confinement by increasing the compressive strength of test cylinders. In case of test cylinders with higher compressive strength, FRP wraps increased the compressive strength but decreased the compressive sham of concrete test cylinders, that resulted in prominent brittle failure mode. The failure of confined concrete was induced by the rupture of FRP material at the stain, being much smaller than the ultimate strain of FRP material.

The strain measurement on the aluminum alloy welded transition joint (알루미늄 合金 異材熔接部의 變形率測定)

  • 옹장우;전제춘;오상진
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.10 no.5
    • /
    • pp.625-634
    • /
    • 1986
  • The strain distribution on a welded aluminum alloy transition joint produced by a static tensile load has been measured using a moire method combined with photoelastic coating method. The test specimens were made of aluminum alloy 6061-T6 and 2014-T6 butt welded with ER-4043 filler metal, and were post welded heat treated (solid solution heat treatment 502.deg. C 70min.) and precipitated (artificial aging 171.deg. C 600min.) to cause an abrupt change of mechanical properties between the base metals and weld metal. The photoelastic epoxy rubber was cemented on the specimen grating which had been reproduced on the specimen surface by using an electropolishing. The measurements were compared with strains computed by Finite Element Analysis. The following results were abtained. (1) The maximum strain were distributed along the center line in the transverse directiion of the weld metal. (2) The strain gradient along the fusion line increased approaching the V-groove tip and the maximum value was observed at a quarter of width from the V-groove tip. (3) The moire method combined with photoelastic coating was proved very useful for real time strain measurement in the welded aluminum alloy transition joint.

Ice Load Estimation Procedures for IBRV ARAON by Analyzing Shear Strain Data Measured in Arctic Sea (쇄빙연구선 아라온호의 북극해 실선 계측 전단변형 데이터 분석을 통한 빙하중 산정 기법 고찰)

  • Min, Jung Ki;Choi, Kyungsik;Cheon, Eun-Jee;Kim, Jin Myung
    • Journal of Ocean Engineering and Technology
    • /
    • v.30 no.6
    • /
    • pp.468-473
    • /
    • 2016
  • This paper focuses on the estimation of local ice loads exerted from ship-ice interaction processes. The Korean IBRV ARAON was used to perform field ice trials during her 2015 Arctic voyage. During ARAON's general ice transit, a total of 72 channels of data from both strain gauges on the inner hull plates and those installed on the transverse frames of the ARAON's bow section structures were analyzed to calculate the local ice loads. The local ice loads estimated from the analysis of the shear strain data measured on the side frames were compared to those from the hull plate pressures.

A General and Versatile XFINAS 4-node Co-Rotational Resultant Shell Element for Large Deformation Inelastic Analysis of Structures (구조물의 대변형 비탄성 해석을 위한 범용 목적의 XFINAS 4절점 순수 변위 합응력 쉘요소)

  • Kim, Ki Du;Lee, Chang Soo
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.26 no.3A
    • /
    • pp.447-455
    • /
    • 2006
  • A general purpose of 4-node co-rotational resultant shell element is developed for the solution of nonlinear problems of reinforced concrete, steel and fiber-reinforced composite structures. The formulation of the geometrical stiffness presented here is defined on the mid-surface by using the second order kinematic relations and is efficient for analyzing thick plates and shells by incorporating bending moment and transverse shear resultant forces. The present element is free of shear locking behavior by using the ANS (Assumed Natural Strain) method such that the element performs very well as thin shells. Inelastic behaviour of concrete material is based on the plasticity with strain hardening and elasto-plastic fracture model. The plasticity of steel is based on Von-Mises Yield and Ivanov Yield criteria with strain hardening. The transverse shear stiffness of laminate composite is defined by an equilibrium approach instead of using the shear correction factor. The proposed formulation is computationally efficient and versitile for most civil engineering application and the test results showed good agreement.

Elastic-Plastic Stress Distributions Behavior in the Interface of SiC/Ti-15-3 MMC under Transverse Loading(I) (횡하중을 받는 SiC/Ti-15-3 MMC 복합재 계면영역에서의 탄소성 응력장분포거동(I))

  • Kang Ji-Woong;Kim Sang-Tae;Kwon Oh-Heon
    • Journal of the Korean Society of Safety
    • /
    • v.19 no.4 s.68
    • /
    • pp.25-30
    • /
    • 2004
  • Unidirectional fiber-metal matrix composites have superior mechanical properties along the longitudinal direction. However, the applicability of continuous fiber reinforced MMCs is somewhat limited due to their relatively poor transverse properties. Therefore, the transverse properties of MMCs are significantly influenced by the properties of the fiber/matrix interface. In this study, the interfacial stress states of transversely loaded unidirectional fiber reinforced metal matrix composites investigated by using elastic-plastic finite element analysis. Different fiber volume fractions $(5-60\%)$ were studied numerically. The interface was treated as thin layer (with different properties) with a finite thickness between the fiber and the matrix. The fiber is modeled as transversely isotropic linear-elastic, and the matrix as isotropic elastic-plastic material. The analyses were based on a two-dimensional generalized plane strain model of a cross-section of an unidirectional composite by the ANSYS finite element analysis code.

The Numerical Simulation of Flow Field and Heat Transfer around 3-D Tube Banks (3차원 튜브 뱅크 주위의 난류 유동장 및 열전달에 대한 수치 해석적 연구)

  • Park, S.K.;Kim, K.W.;Ryou, H.S.;Choi, Y.K.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.8 no.3
    • /
    • pp.375-385
    • /
    • 1996
  • Turbulent flow and heat transfer characteristics around staggered tube banks were studied using the 3-D Navier-Stokes equations and energy equation governing a steady incompressible flow, which were reformulated in a non-orthogonal coordinate system with cartesian velocity components and discretized by the finite volume method with a non-staggered variable arrangement. The predicted turbulent kinetic energy using RNG $k-{\varepsilon}$ model was lower than that of standard $k-{\varepsilon}$ model but showed same result for mean flow field quantities. The prediction of the skin friction coefficient using RNG $k-{\varepsilon}$ model showed better trend with experimental data than standard $k-{\varepsilon}$ model result. The inclined flow showed higher velocity and skin friction coefficient than transverse flow because of extra strain rate ($\frac{{\partial}w}{{\partial}y}$). Also, this was why the inclined flow showed higher local heat transfer coefficient than the transverse flow.

  • PDF

Failure analysis of prestressing steel wires

  • Toribio, J.;Valiente, A.
    • Steel and Composite Structures
    • /
    • v.1 no.4
    • /
    • pp.411-426
    • /
    • 2001
  • This paper treats the failure analysis of prestressing steel wires with different kinds of localised damage in the form of a surface defect (crack or notch) or as a mechanical action (transverse loads). From the microscopical point of view, the micromechanisms of fracture are shear dimples (associated with localised plasticity) in the case of the transverse loads and cleavage-like (related to a weakest-link fracture micromechanism) in the case of cracked wires. In the notched geometries the microscopic modes of fracture range from the ductile micro-void coalescence to the brittle cleavage, depending on the stress triaxiality in the vicinity of the notch tip. From the macroscopical point of view, fracture criteria are proposed as design criteria in damage tolerance analyses. The transverse load situation is solved by using an upper bound theorem of limit analysis in plasticity. The case of the cracked wire may be treated using fracture criteria in the framework of linear elastic fracture mechanics on the basis of a previous finite element computation of the stress intensity factor in the cracked cylinder. Notched geometries require the use of elastic-plastic fracture mechanics and numerical analysis of the stress-strain state at the failure situation. A fracture criterion is formulated on the basis of the critical value of the effective or equivalent stress in the Von Mises sense.