• 제목/요약/키워드: Shear Behavior

검색결과 3,821건 처리시간 0.032초

Wall slip of vaseline in steady shear rheometry

  • Song, Ki-Won;Chang, Gap-Shik;Koo, Ja-Seung
    • Korea-Australia Rheology Journal
    • /
    • 제15권2호
    • /
    • pp.55-61
    • /
    • 2003
  • The steady shear flow properties of vaseline generally used as a base of the pharmaceutical dosage forms were studied in the consideration of wall slip phenomenon. The purpose of this study was to show that how slip may affect the experimental steady-state flow curves of semisolid ointment bases and to discuss the ways to eliminate (or minimize) wall slip effect in a rotational rheometer. Using both a strain-controlled ARES rheometer and a stress-controlled AR1000 rheometer, the steady shear flow behavior was investigated with various experimental conditions ; the surface roughness, sample preparation, plate diameter, gap size, shearing time, and loading methods were varied. A stress-controlled rheometer was suitable for investigating the flow behavior of semisolid ointment bases which show severe wall slip effects. In the conditions of parallel plates attached with sand paper, treated sample, smaller diameter fixture, larger gap size, shorter shearing time, and normal force control loading method, the wall slip effects could be minimized. A critical shear stress for the onset of slip was extended to above 10,000 dyne/$\textrm{cm}^2$. The wall slip effects could not be perfectly eliminated by any experimental conditions. However, the slip was delayed to higher value of shear stress by selecting proper fixture properties and experimental conditions.

발파 암반-콘크리트 경계면에서의 전단거동특성에 대한 수치해석적 연구 (A Numerical Study on Shear Behavior of the Interface between Blasted Rock and Concrete)

  • 민경조;고영훈;;오세욱;김정규;정문경;조상호
    • 화약ㆍ발파
    • /
    • 제37권4호
    • /
    • pp.26-35
    • /
    • 2019
  • 타정식 현수교의 중력식 앵커리지를 설계하는 데 있어, 지반과 콘크리트 앵커블록 사이에 작용하는 접촉 마찰력은 교량의 주케이블의 장력을 지지하는데 많은 기여를 하고 있기 때문에 콘크리트와 암반 사이 접촉면의 마찰 및 전단 저항 특성을 이해하는 것이 중요하다. 이를 위해, 본 연구에서는 휴대용 레이저 스캐너를 활용하여 발파 바닥면을 스캐닝하였으며, 이를 바탕으로 3차원 모델링 및 거칠기를 정량적으로 분석하였다. 또한 발파 바닥암반 단면 데이터를 활용하여, 발파 바닥암반-콘크리트 경계면을 갖는 모델을 생성하였다. 동적파괴과정해석기법(DFPA-3D)를 활용하여, 해당 모델에 대한 직접 전단시험 모사를 수행하였으며, 이를 바탕으로 발파 바닥암반-콘크리트 접촉면에 대한 전단파괴 거동을 확인 및 분석하였다.

Monotonic behavior of C and L shaped angle shear connectors within steel-concrete composite beams: an experimental investigation

  • Shariati, Mahdi;Tahmasbi, Farzad;Mehrabi, Peyman;Bahadori, Alireza;Toghroli, Ali
    • Steel and Composite Structures
    • /
    • 제35권2호
    • /
    • pp.237-247
    • /
    • 2020
  • Shear connectors are essential elements in the design of steel-concrete composite systems. These connectors are utilized to prevent the occurrence of potential slips at the interface of steel and concrete. The two types of shear connectors which have been recently employed in construction projects are C- and L-shaped connectors. In the current study, the behavior of C and L-shaped angle shear connectors is investigated experimentally. For this purpose, eight push-out tests were composed and subjected to monotonic loading. The load-slip curves and failure modes have been determined. Also, the shear strength of the connectors has been compared with previously developed relationships. Two failure modes of shear connectors were observed: 1) concrete crushing-splitting and 2) shear connector fracture. It was found that the L-shaped connectors have less shear strength compared to C-shaped connectors, and decreasing the angle leg size increases the shear strength of the C-shaped connectors, but decreases the relative ductility and strength of L-shaped connectors.

Shear behavior of short square tubed steel reinforced concrete columns with high-strength concrete

  • Li, Xiang;Zhou, Xuhong;Liu, Jiepeng;Wang, Xuanding
    • Steel and Composite Structures
    • /
    • 제32권3호
    • /
    • pp.411-422
    • /
    • 2019
  • Six shear-critical square tubed steel reinforced concrete (TSRC) columns using the high-strength concrete ($f_{cu,150}=86.6MPa$) were tested under constant axial and lateral cyclic loads. The height-to-depth ratio of the short column specimens was specified as 2.6, and the axial load ratio and the number of shear studs on the steel shape were considered as two main parameters. The shear failure mode of short square TSRC columns was observed from the test. The steel tube with diagonal stiffener plates provided effective confinement to the concrete core, while welding shear studs on the steel section appeared not significantly enhancing the seismic behavior of short square TRSC columns. Specimens with higher axial load ratio showed higher lateral stiffness and shear strength but worse ductility. A modified ACI design method is proposed to calculate the nominal shear strength, which agrees well with the test database containing ten short square TSRC columns with shear failure mode from this study and other related literature.

Flexural and shear behavior of bolt-connected U-shaped steel beams filled with concrete

  • Chul-Goo Kim;Sang-Hyun Lee
    • Steel and Composite Structures
    • /
    • 제53권1호
    • /
    • pp.61-75
    • /
    • 2024
  • Thin-walled concrete-filled U-shaped steel beams have been recently used in building structures for shortening the construction period and cost efficiency of structural members. In this study, the flexural and shear behavior of newly developed bolt-connected U-shaped steel beams filled with concrete was experimentally evaluated considering load conditions for positive and negative moments, and types of U-shaped steel sections. Because the cross sections are not symmetrical about a horizontal axis, compressive buckling of bottom plates was observed along with web shear buckling under negative moment loading, while the slab concrete under compression was crushed under a positive moment loading. Despite such different shear failure modes depending on load conditions, the shear strength of the composite beams can be conservatively predicted using AISC 360-16 and Eurocode 4. Although the shear contribution of filled concrete is neglected according to the current design codes, the shear capacity of the steel web considering the shear buckling coefficient corresponding to the web width-to-thickness ratio reasonably predicts the test results. In addition, for deep composite beams, the longitudinal lips of a U-shaped steel section anchored into filled concrete can improve the interfacial bond between steel and concrete, thereby enhancing the shear contribution of the steel web.

탄소섬유쉬트로 보강된 철근콘크리트 보의 휨거동에 전단키와 U 스터립이 미치는 영향 (Effect of Shear Key and U strip on Flexural Behavior of Reinforced Concrete Beams Strengthened by CFS(Carbon Fiber Sheet))

  • 최홍식;이진용;이성태;이시우;허권
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
    • /
    • pp.88-91
    • /
    • 2004
  • It is generally known that the bonding strength of RC(Reinforced Concrete) flexural members strengthened by fiber sheet composites are sufficient and the bonding failure does not occur until the sheet failed. However, many researchers have been reported that, before the failure of the sheet, the bonding failure happens even though the bonding length is sufficient. This study was carried out to evaluate the effectiveness of shear key and U strip on flexural behavior of reinforced concrete beam structures. The ply number of CFS(Carbon Fiber Sheet), location of shear key, and existence or not of U strip were selected as the main test variables. Test results show that the behavior of a beam of which shear key is located in the nearby. of support and U strip is not existent, and having CFS of 1 ply is mostly improved.

  • PDF

돌핀의 높이와 경사에 따른 돌핀의 거동 특성 (Dynamic Behavior of a Breasting Dolphin with Various Dolphin Heights and Slopes)

  • 윤경석;조원철;조철희
    • 한국해양공학회지
    • /
    • 제23권6호
    • /
    • pp.44-52
    • /
    • 2009
  • In this study, the behavior of a breasting dolphin with various dolphin heights and formations in the coastal area of Incheon was investigated. The dynamic deflection, shear stress, and moment of the pile were analyzed using the coefficient of the horizontal subgrade reaction that resulted from loading tests of different DWT (Dead Weight Tonnage). In the case of a vertical pile type dolphin, the deflection, shear stress, and moment increased as the dolphin height increased. In the case of the battered pile type dolphin, small values of shear stress and moment were shown at a low dolphin height, and the characteristics of the dynamic behavior of the dolphin showed that the deflection, shear stress, and moment increased as the pile slope of the dolphin decreased or the DWT increased.

Effects of Matrix Ductility on the Shear Performance of Precast Reinforced HPFRCC Coupling Beams

  • Yun Hyun-Do;Kim Sun-Woo;Jeon Esther;Park Wan Shin
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
    • /
    • pp.53-56
    • /
    • 2005
  • This paper investigates the effect of ductile deformation behavior of high performance hybrid fiber-reinforced cement composites (HPHFRCCs) on the shear behavior of coupling beams to lateral load reversals. The matrix ductility and the reinforcement layout were the main variables of the tests. Three short coupling beams with two different reinforcement arrangements and matrixes were tested. They were subjected to cyclic loading by a suitable experimental setup. All specimens were characterized by a shear span-depth ratio of 1.0. The reinforcement layouts consisted of a classical scheme and diagonal scheme without confining ties. The effects of matrix ductility on deflections, strains, crack widths, crack patterns, failure modes, and ultimate shear load of coupling beams have been examined. The combination of a ductile cementitious matrix and steel reinforcement is found to result in improved energy dissipation capacity, simplification of reinforcement details, and damage-tolerant inelastic deformation behavior. Test results showed that the HPFRCC coupling beams behaved better than normal reinforced concrete control beams. These results were produced by HPHFRCC's tensile deformation capacity, damage tolerance and tensile strength.

  • PDF

이형 용접철망을 전단철근으로 사용한 철근콘크리트 연속 깊은 보의 구조적 거동에 대한 실험적 연구 (An Experimental Study on the Structural Behavior of Reinforced Concrete Continuous Deep Beams Using Welded Deformed Wire Fabric as Shear Reinforcements)

  • 양근혁;정헌수
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
    • /
    • pp.95-98
    • /
    • 2005
  • The objective of this experimental study was to understand the structural behavior of reinforced concrete continuous deep beams with welded deformed wire fabric(WWF) as shear reinforcement. The structural behavior of deep beams reinforced with WWF was compared with that of deep beams reinforced with orthogonal shear reinforcement which had standard anchorage corresponding to ACI 318-02. Test results showed that the load transferring capacity and the control of splitting cracks in the strut of WWF were almost as effective as those of orthogonal shear reinforcement with standard anchorage.

  • PDF

비배수 전단강도에 따른 압입식 경량강재앵커블록의 거동 특성 (Characteristics of Behavior of Pressurized light-weight steel Anchor according to undrained shear strength)

  • 허열;안광국;박경수;이용준;강홍식
    • 한국지반공학회:학술대회논문집
    • /
    • 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
    • /
    • pp.219-224
    • /
    • 2009
  • In this study, the characteristics of pullout behavior of Pressurized light-weight steel Anchor was investigated through centrifuge model tests considering pull-out angle $0^{\circ}$ with changing undrained shearstrength(0~1, 2~4, 5~7kPa) of clay. According to the results of tests, the yield pullout load of clay ground was gradually increased up to 30% as undrained shear strength was increased. Therefore, it was known that the yield pullout load was affected by increasing the undrained shear strength, in addition, the pattern of behavior was not changed.

  • PDF