• Title/Summary/Keyword: Cyclic loads

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Verification for the Cyclic Shear Behavior of Rough Granite Joint Using Constitutive Equation (구성방정식을 이용한 거친 화강암 절리면의 주기전단거동 특성규명)

  • 김대상;박인준;이희석
    • Journal of the Korean Geotechnical Society
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    • v.18 no.1
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    • pp.141-152
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    • 2002
  • Although a number of constitutive models have been proposed to define the behavior of geotechnical materials including elastic, plastic, and dynamic response, flew numerical models have been developed for the cyclic shear behavior of rock joints or interfaces. Such realistic constitutive models play an important role in analyzing and predicting the response of joints under dynamic loads. The purpose of this research is to verify the constitutive model modified for rough granite joints based on Disturbed State Concept(DSC) model, which has been successfully verified with respect to other materials such as dry sand-steel interface and wet sand-concrete interface. Furthermore, DSC model is compared and verified with respect to cyclic shear tests and numerical analysis results based on Plesha model. Based on the results of this research, it can be stated that DSC model is capable of characterizing the cyclic shear behavior of rough granite joints under dynamic loads.

Design parameters on the fatigue characteristics of a co-cured double lap joint (양면겹치기 동시경화조인트의 피로특성에 영향을 미치는 설계변수에 관한 연구)

  • 신금철;이정주
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2002.05a
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    • pp.5-8
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    • 2002
  • The use of the co-cured joining method for composite structures is attractive due to several benefits. However, since the design stress level in cyclic loads is often smaller than the joint strength obtained from the static tensile load test, it is important to establish proper fatigue design criteria. Although some researchers have reported on co-cured joints, there are only a few papers published on the fatigue characteristics of co-cured joints. In this paper, the effect of bond parameters on the fatigue characteristics of a steel-composite co-cured double lap joint under cyclic tensile loads was experimentally investigated. We considered the surface roughness of the steel adherend and the stacking sequence of the composite adherend as bond parameters. A fatigue failure mechanism of the co-cured double lap joint was explained systematically by investigating the surfaces of failed specimens.

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An Experimental Study on the Relocating Plastic Hinging Zones of Reinforced Concrete Beams Subjected to Cyclic Loads (반복하중을 받는 철근콘크리트 보의 소성힌지 이동에 관한 실험적 연구)

  • 김윤일;최창식;천영수;이리형
    • Proceedings of the Korea Concrete Institute Conference
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    • 1989.10a
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    • pp.77-82
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    • 1989
  • In this paper an experimental approach of the relocation plastic hinging zones of nine reinforced concrete exterior beam-column subassemblages under cyclic loads was tried. The main parameters of the testing program were location of the plastic hinge, difference of the special reinforcement, inclined or intermediate layers of longitudinal reinforcement, applied maximum shear stress. The conclusions presented herein are based on the limited texts conducted. Inclined or intermediate layers of longitudinal reinforcement and extra top and bottom steel in the beam over a specific legnth can be used to move the beam plastic hinging zone away from the column face. But, for the use of intermediate layers of longitudinal reinforcement, sheat reinforcement detail need further investigation.

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Experimental Study on the Hysteretic Behavior of R/C Low-Rise Shear Walls under Cyclic Loads (반복하중을 받는 철근콘크리트 저형 전단벽의 이력거동에 관한 실험적 연구 (I))

  • 최창식;이용재;윤현도;이리형
    • Proceedings of the Korea Concrete Institute Conference
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    • 1991.04a
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    • pp.75-80
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    • 1991
  • Results of an experimental investigation of low-rise reinforced concrete shear walls with rectangular cross section under cyclic loads are discussed and evaluated. Two half scale models of test specimens with height to length ratio of 0.75 were experimented. The dimension of all walls is 1500mm wide $\times$ 950 mm high $\times$ 100 mm thick for all specimens and the section of all boundary at both ends is 100 mm $\times$ 200mm. Main variables are : horizontal shear reinforcement ratios and reinforcement details(including crossed diagonal shear reinforcements in SWR2 specimen) In SWR2 specimen, maximum strength and consequently dissipating energy index were 1.15~1.21 and 1.48 times greater than those of SWR1 specimen, respectively.

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Numerical study of steel box girder bridge diaphragms

  • Maleki, Shervin;Mohammadinia, Pantea;Dolati, Abouzar
    • Earthquakes and Structures
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    • v.11 no.4
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    • pp.681-699
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    • 2016
  • Steel box girders have two webs and two flanges on top that are usually connected with shear connectors to the concrete deck and are also known as tub girders. The end diaphragms of such bridges comprise of a stiffened steel plate welded to the inside of the girder at each end. The diaphragms play a major role in transferring vertical and lateral loads to the bearings and substructure. A review of literature shows that the cyclic behavior of diaphragms under earthquake loading has not been studied previously. This paper uses a nonlinear finite element model to study the behavior of the end diaphragms under gravity and seismic loads. Different bearing device and stiffener configurations have been considered. Affected areas of the diaphragm are distinguished.

A Study on the Effects of the Design Parameters and Sealing Mechanism of the Exhaust Gas in Engine Exhaust System (엔진 배기계의 배기가스 누설 메카니즘과 설계인자들의 영향에 관한 연구)

  • Choi, B.L.
    • Journal of Power System Engineering
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    • v.14 no.4
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    • pp.37-42
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    • 2010
  • This paper deals with the sealing mechanism of the gasket component and the effects of design parameters for the exhaust manifold. The finite element model includes hot-end exhaust system and a simplified gasket model supplied by ABAQUS software. The mechanical behaviors of bead and body of a gasket are measured after several times of cyclic loads by gasket supplier. From the finite element analysis due to the cyclic thermal loads, the flange of exhaust manifold shows thermal expansion and contraction in longitudinal direction as well as convex and concave deformations with respect to the engine cylinder head. And, the contact pressures of the gasket beads suddenly changes by normal deformation of inlet flanges. Therefore, the magnitudes of contact pressures could be used to determine the sealing characteristics of the exhaust gas in the exhaust system. The distributions of contact pressures in gasket bead lines shows a good agreement with the engine test results.

Nonlinear Analysis of High-Strength R/C Columns Subjected to Reversed Cyclic Loads with Axial Compression (축력과 반복횡력을 받는 고강도 R/C 기둥의 비선형 해석)

  • 신성우;서선민;한범석;안종문;반병열;이광수
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.565-570
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    • 2000
  • The objective of this paper is to analyse the high-strength concrete columns subjected to reversed cyclic and axial loads by using nonlinear analysis model and compare the experimental results with analysis. The analytical parameters are the compressive strength of concrete, spacing of lateral reinforcement and lateral reinforcement ratio. In this study, the proposed analytical model takes ito account the influence of confined concrete, tension stiffening and strain hardening of steel. The high-strength concrete columns are used to model fiber section element. The analysis results are shown comparatively good prediction on envelope curve, accumulative dissipated energy, deformability and so on.

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Numerical modelling of soil-foundation interaction by a new non-linear macro-element

  • Khebizi, Mourad;Guenfoud, Hamza;Guenfoud, Mohamed
    • Geomechanics and Engineering
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    • v.14 no.4
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    • pp.377-386
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    • 2018
  • This paper focuses on the development of a new non-linear macro-element for the modelling of soil-foundation interaction. Material and geometrical nonlinearities (soil yielding and foundation uplift respectively) are taken into account in the present macro-element to examine the response of shallow foundations under monotonic and cyclic loads. Several applications of soil-foundation systems are studied. The results obtained from these applications are in very favourable agreement with those obtained through other numerical models in the literature.

Nonlinear Analysis of R/C Shear Walls Subjected to Inelastic Cyclic Loads by finite Element Mettled (비탄성 반복하중을 받는 철근콘크리트 전단벽의 비선형 유한요소 해석)

  • 윤현도;오영훈;최창식;이리형
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1990.10a
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    • pp.55-60
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    • 1990
  • The objective of this study is to predict the nonlinear behavior of reinforced concrete shear walls, with the reinforcement uniformly distributed, under reversed cyclic loads. This study introduces joint Element Model which formulates the pulling out of rebars, slipping and intrusion of junction planes. The applicability of this study was experimental verfied by specimens SW1, SW2 and SW3 tested by authors, Wall1 by Paulay, SW16 and SW19 by Sheu. In almost specimen, the ratio of analytical to experimental maximum shear stress is within approximately 5%. In case of energy dissipation and maximum drift, the analytical results fully coincide with those of experiment.

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Cyclic Behavior of Interior Joints in Post Tensioned Flat Plate Slab Systems (내부 포스트 텐션 플랫 플레이트 슬래브 기둥 접합부의 이력거동)

  • Kee Seong Hoon;Han Sang Whan;Ha Sang-Su;Lee Li Ryung
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05a
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    • pp.107-110
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    • 2005
  • In general, post tensioned (PT) flat plate slab systems have been used as a Gravity Load Resisting System (GLRS) in buildings. Thus, these systems should be constructed with Lateral Force Resisting Systems (LFRS) such as shear walls and moment resisting frames. When lateral loads such as winds or earthquakes occur, lateral load resisting systems undergo displacement by which connected gravity systems experience lateral displacement. Therefore, GLRS should have some lateral displacement capacity in order to hold gravity loads under severe earthquakes and winds. Since there are the limited number of researches on PT flat plate slab systems, the behavior of the systems have not been well defined. This study investigated the cyclic behavior of post tensioned flat plate slab systems. For this purpose, an experimental test was carried out using 4 interior PT flat plate slab-column specimens. All specimens have bottom reinforcement in the slab around the slab-column connection. Test variables of this experimental study are vertical load level and tendon distribution patterns.

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