• International Journal of Concrete Structures and Materials
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• 제9권3호
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• pp.267-281
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• 2015

Six full-scale prestressed concrete (PC) I-beams with steel fibers were tested to failure in this work. Beams were cast without any traditional transverse steel reinforcement. The main objective of the study was to determine the effects of two variables-the shear-span-to-depth ratio and steel fiber dosage, on the web-shear and flexural-shear modes of beam failure. The beams were subjected to concentrated vertical loads up to their maximum shear or moment capacity using four hydraulic actuators in load and displacement control mode. During the load tests, vertical deflections and displacements at several critical points on the web in the end zone of the beams were measured. From the load tests, it was observed that the shear capacities of the beams increased significantly due to the addition of steel fibers in concrete. Complete replacement of traditional shear reinforcement with steel fibers also increased the ductility and energy dissipation capacity of the PC I-beams.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.302-307
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• 2004

This paper reviewed characteristics of fatigue crack behavior observed by changing various shapes of initial crack and magnitudes of loading in compact tension shear(CTS) specimen subjected to shear loading. In the high-loading condition, fatigue crack under shear loading propagated branching from the pre-crack tip. Meanwhile, the secondary fatigue crack in the low-loading condition which was created in the notch root due to friction on the pre-crack face grew to a main crack. Influenced by the mode II loading condition, fatigue crack propagation retardation appeared in the initial propagation region due to the reduction of crack driving force and friction on crack face. In both cases, however, fatigue cracks grew in tensile mode type. Propagation path of fatigue crack under the shear loading was 70 degree angle from the initial crack regardless of its shape and load magnitude.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.561-566
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• 2001

Load at steel beam column joints transfered by beam depend on bond strength between concrete and steel tube. But it is different to transmit a load efficiently in the established concrete filled steel tubular column. Therefore, shear-connector is demanded for transfering loads efficiently. An ascent of bond stress and a transmission of load after debonding are expected by a reinforcement of shear-connector

• 한국지진공학회논문집
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• 제28권2호
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• pp.77-83
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• 2024

The design shear strength equations of RC shear walls have been developed based on their performance under in-plane (IP) loads, thereby failing to account for the potential performance degradation of shear strength when subjected to simultaneous out-of-plane (OOP) loading. Most of the previous experimental studies on RC walls have been conducted in one direction under quasi-static conditions, and due to the difficulty in experimental planning, there is a lack of research on cyclic loading and results under multi-axial loading conditions. During an earthquake, shear walls may yield earlier than their design strength or fail unexpectedly when subjected to multi-directional forces, deviating from their intended failure mode. In this paper, nonlinear analysis in finite element models was performed based on the results of cyclic loading experiments on reinforced concrete shear walls of auxiliary buildings. To investigate the reduction trend in IP shear capacity concerning the OOP load ratio, parametric analysis was conducted using the shear wall FEM. The analysis results showed that as the magnitude of the OOP load increased, the IP strength decreased, with a more significant effect observed as the size of the opening increased. Thus, the necessity to incorporate this strength reduction as a factor for the OOP load effect in the wall design strength equation should be discussed by performing various parametric studies.

• 한국소음진동공학회논문집
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• 제18권8호
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• pp.849-855
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• 2008

다양한 조임 조건에서 기계적 조인트의 컨택 특성 파라미터를 유도하기 위하여 컨택 공진을 기반으로 하는 실험적 방법을 개발하였다. 기계적 조인트의 전단 컨택 강성과 감쇠의 파라미터는 접촉 표면간의 표면 처리, 윤활 유무, 그리고 조임력과 전단력의 의한 영향과 같은 여러 가지 물리적 조인터 파라미터와 연계하여 고찰하였다. 제안된 실험적 방법을 사용하여 전단 컨택 강성 값은 조임력과 전단력이 커짐에 따라 증가하는 것을 발견하였다. 또한 컨택 감쇠 비 값은 대부분 조임력과 상관없이 일정 값을 나타내지만 전단력이 커짐에 따라 감소하였다. 추가로, 전단 강성 값과 컨택 감쇠 비는 매끄러운 표면에서보다 거친 표면에서 더 크게 나타남을 알 수 있었다.

• Steel and Composite Structures
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• 제17권6호
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• pp.967-980
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• 2014

In regions of high shear forces in composite bridges, headed stud shear connectors need to be arranged with a small spacing in order to satisfy the design requirement of resisting the high interface shear force present at this location. Despite this, studies related to groups of headed studs are somewhat rare. This paper presents an investigation of the static behaviour of grouped stud shear connectors in high-strength concrete. Descriptions are given of five push-out test specimens with different arrangements of the studs that were fabricated and tested, and the failure modes, load-slip response, ultimate load capacities and related slip values that were obtained are reported. It is found that the load-slip equation given by some researchers based on a single stud shear connector in normal strength concrete do not apply to grouped stud shear connectors in high-strength concrete, and an algebraic load-slip expression is proposed based on the test results. Comparisons between the test results and the formulae provided by some national codes show that the equations for the ultimate capacity provided in these codes are conservative when used for connectors in high-strength concrete. A reduction coefficient is proposed to take into account the effect of the studs being in a group.

• Structural Engineering and Mechanics
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• 제27권2호
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• pp.135-148
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• 2007

A new finite shear wall element model and a method for calculation of 3D multi-storied only shear walled or shear walled - framed structures using finite shear wall elements assumed ideal elasto - plastic material are developed. The collapse load of the system subjected to factored constant gravity loads and proportionally increasing lateral loads is calculated with a method of load increments. The shape functions over the element are determined as a cubic variation along the story height and a linear variation in horizontal direction because of the rigid behavior of the floor slab. In case shear walls are chosen as only one element in every floor, correct solutions are obtained by using this developed element. Because of the rigid behavior of the floor slabs, the number of unknowns are reduced substantially. While in framed structures, classical plastic hinge hypothesis is used, in nodes of shear wall elements when vertical deformation parameter is exceeded ${\varepsilon}_e$, this node is accepted as a plastic node. While the system is calculated with matrix displacement method, for determination of collapse safety, plastic displacements and plastic deformations are taken as additional unknowns. Rows and columns are added to the system stiffness matrix for additional unknowns.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.410-413
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• 2006

The ㄱ type perfobond rib shear connector is a ㄱ type flat steel plate with a number of holes punched through. This connector can be effectively used in girder with high shear. The ㄱ type perfobond rib shear connector exhibit very stiff behaviour under service load conditions and also had the characteristic of retaining a significant amount of load after the attainment of ultimate capacity. The ㄱ type perfobond rib shear connector with safety factor of 3 is applied shear connector of CFT composite girder. From static test result of CFT composite girder, relative displacement of 0.01mm measured at the service load moment. At design of the ㄱ type perfobond rib shear connector, applying safety factor of 3 was more conservative than test result.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.78-79
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• 2014

This study is concerned with the VS shear reinforcement that it can be installed easily in filed as product at the factory and seismic performance can be achieved. The method of study is as follows. first, we researched constructability and economy of existing construction method. Secondly, we made specimen and were examined structural performance tests in order to verify the performance of the shear reinforcement for lateral force like seismic load. As a result, developed VS shear reinforcement increased in shear strength and stiffness of reinforcement, structural safety is judged to be increased.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1999년도 봄 학술발표회 논문집
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• pp.187-194
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• 1999

Laminated rubber bearings are widely used as a key component in seismic isolation of structural systems subjected to earthquake loadings. The combination of rubber layers and reinforcing steel shims makes the bearings conditionally unstable similar to buckling of ordinary columns. The shear flexibility of these short columns can lead to relatively low buckling Toads which may be further reduced when high shear strains are simultaneously imposed As an analytical approach, the area reduction formula has been proposed to account for the reduction in buckling load due to shear, but the degree of conservatism is unknown. In order to complement analytical approaches, a non-linear finite element analysis can be used. In this paper, a numerical study which aims at determining the effect of high shear strain on the critical load of elastomeric bearings is presented. From the load-displacement curve at each specified shear displacement, the buckling load can be obtained using the Southwell procedures. The results obtained are then compared against the theoretical predictions in order to examine the validity and the conservatism of the theoretical formulas.