• Structural Engineering and Mechanics
• /
• v.18 no.4
• /
• pp.493-516
• /
• 2004

This paper addresses the behavior and strength of structural walls with a concrete compressive strength exceeding 69 MPa. This information also enhances the current database for improvement of design recommendations. The objectives of this investigation are to study the effect of axial-load ratio on seismic behavior of high-strength concrete flexural walls. An analysis has been carried out in order to assess the contribution of deformation components, i.e., flexural, diagonal shear, and sliding shear on total displacement. The results from the analysis are then utilized to evaluate the prevailing inelastic deformation mode in each of wall. Moment-curvature characteristics, ductility and damage index are quantified and discussed in relation with axial stress levels. Experimental results show that axial-load ratio have a significant effect on the flexural strength, failure mode, deformation characteristics and ductility of high-strength concrete structural walls.

• Journal of the Korean Wood Science and Technology
• /
• v.19 no.2
• /
• pp.40-55
• /
• 1991

To investigate the influence of cross section geometries on the behavior of composite beams in the case of small span to depth ratio and deep beams. the static flexural behavior of composite I-beams and Box- beams was evaluated. 12 types of composite I -beams composed of LVL flanges and particleboard or plywood web and 3 types of composite Box-beams composed of LVL flanges and plywood web were tested under one-point loading. The load-deflection curves were almost linear to failure, therefore, the behavior of tested composite beams was elastic. The theoretical flexural rigidity of composite beams was calculated and compared with observed flexural rigidity. The highest value was found in I-W type beams and the lowest value was found in G-P type beams. The difference between theoretical and observed flexural rigidity was small. Theoretical total deflection of tested composite beams was calculated using flexural rigidity and compared with actual deflection. Shear deflection of these beams was evaluated by the approximation method, solid crosss section method and elementary method. The difference between actual deflection and expected deflection was not found in D, E and F type beams. This defference was small in G, H and I type beams or Box-beam.

• Steel and Composite Structures
• /
• v.18 no.4
• /
• pp.925-946
• /
• 2015

This paper presents a new cost-effective hybrid GFRP-Concrete deck system that the GFRP panel serves as both tensile reinforcement and stay-in-place form. In order to understand the fatigue behavior of such hybrid deck, fatigue test on a full-scale specimen under sagging moment was conducted, and a series of static tests were also carried out after certain repeated loading cycles. The fatigue test results indicated that such hybrid deck has a good fatigue performance even after 3.1 million repeated loading cycles. A three-dimensional finite element model of the hybrid deck was established based on experimental work. The results from finite element analyses are in good agreement with those from the tests. In addition, flexural fatigue analysis considering the reduction in flexural stiffness and modulus under cyclic loading was carried out. The predicted flexural strength agreed well with the analytical strength from finite element simulation, and the calculated fatigue failure cycle was consistent with the result based on related S-N curve and finite element analyses. However, the flexural fatigue analytical results tended to be conservative compared to the tested results in safety side. The presented overall investigation may provide reference for the design and construction of such hybrid deck system.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.7 no.2
• /
• pp.158-165
• /
• 2019

The purpose of this study is to investigate analytically the flexural behavior of beam reinforced by an alkali-activated slag-based fiber-reinforced composite. The materials and mixture proportion were selected to manufacture an alkali-activated slag-based fiber-reinforced composite with high tensile strain capacity over 7% and compressive strength and tension tests were performed. The composite showed a compressive strength of 32.7MPa, a tensile strength of 8.43MPa, and a tensile strain capacity of 7.52%. In order to analyze the flexural behavior of beams reinforced by ultra-high-ductile composite, nonlinear sectional analysis was peformed for four types of beams. Analysis showed that the flexural strength of beam reinforced partially by ultra-high-ductile composite increased by 8.0%, and the flexural strength of beam reinforced fully by ultra-high-ductile composite increased by 24.7%. It was found that the main reason of low improvement in flexural strength is the low tensile strain at the bottom of beam. The tensile strain at bottom corresponding to the flexural strength was 1.38% which was 18.4% of tensile strain capacity of the composite.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.18 no.8
• /
• pp.856-863
• /
• 2008

High-rise apartments of shear wall system are governed by flexural behavior like a cantilever beam. Installation of the damper-brace system in a structure governed by flexural behavior is not suitable. Because of relatively high lateral stiffness of the shear wall, a load is not concentrate on the brace and the brace cannot perform a role as a damping device. In this paper, a friction damper applying flexibility of shear wall is proposed in order to reduce the deformation of a structure. To evaluate performance of the proposed friction damper, nonlinear time history analysis is executed by SeismoStruct analysis program and MVLEM(multi vertical linear element model) be used for simulating flexural behavior of the shear wall. It is found that control performance of the proposed friction damper is superior to one of a coupled wall with rigid beam. In conclusion, this study verified that the optimal control performance of the proposed friction damper is equal to 45 % of the maximum shear force inducing in middle-floor beam with rigid beam.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1990.10a
• /
• pp.169-174
• /
• 1990

Fracture tests were carried out in order to investigate the flexural behavior of SFRC (Steel Fiber Reinforced Concrete) structures. Sixty three SFRC beams were used in the tests, the fracture mode, the relationships between loading and strains, and the relationships between loading and mid-span deflections of the beams were observed under the three point bending loading. From the test results, the effects of steel fiber contents and a/h ratio on the concrete flexural behavior were studied, and the stress intensity factors and the flexural strength of SFRC beams were calculated. According to the results of regression analysis, predicting formulas for the flexural strength of SFRC beams are also suggested.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.05a
• /
• pp.418-421
• /
• 2006

Appropriate analysis models for concrete-filled steel tube (CFT) subjected to bending moment were determined to assess flexural behavior of CFT member. Applying this model, finite element analyses was performed and compared against experimental data considering the compressive strength of in-filling material and the composite action between tube shell and in-filling core. Analysis results showed that the FE model proposed in this study is feasible for the analytical investigation of the flexural behavior of CFT member according to loading conditions, effect of compressive strength of various core materials and other design parameters.

• Structural Engineering and Mechanics
• /
• v.12 no.5
• /
• pp.459-474
• /
• 2001

The complete moment-curvature curves of doubly reinforced concrete beams made of normal- or high-strength concrete have been evaluated using a newly developed analytical method that takes into account the stress-path dependence of the constitutive properties of the materials. From the moment-curvature curves and the strain distribution results obtained, the post-peak behavior and flexural ductility of doubly reinforced normal- and high-strength concrete beam sections are studied. It is found that the major factors affecting the flexural ductility of reinforced concrete beam sections are the tension steel ratio, compression steel ratio and concrete grade. Generally, the flexural ductility decreases as the amount of tension reinforcement increases, but increases as the amount of compression reinforcement increases. However, the effect of the concrete grade on flexural ductility is fairly complicated, as will be explained in the paper. Quantitative analysis of such effects has been carried out and a formula for direct evaluation of the flexural ductility of doubly reinforced concrete sections developed. The formula should be useful for the ductility design of doubly reinforced normal- and high-strength concrete beams.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2002.05a
• /
• pp.959-964
• /
• 2002

The purpose of this study is to establish flexural behavior of high-strength concrete by means of both theoretical approach and experimental analysis of beams in which confinement stirrups have been introduced into pure bending zone. The experiment was carried out on full-scale high-strength reinforced concrete beams whose compressive strengths are 400 and 700kgf/cm$^2$, and confined with rectangular closed stirrups. The test results are reviewed in terms of flexural capacity and ductility.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.05a
• /
• pp.524-527
• /
• 2004

Recently, precast concrete products have been increasingly used in the construction of bridges except for special bridges like long-span bridge due to their easy and high-quality construction. Specially the use of precast prestressed concrete hollow box slab bridges is also increased due to the merits in their construction. Thus, an experimental evaluation of flexural behavior of the precast PSC hollow box slab bridges and a development of effective analytical technique for the behavior are necessary. For the development, experimental study on the flexural behavior of the precast bridges up to ultimate states is needed. In this study, two full-scale precast PSC hollow box slab girders are manufactured and full-scale flexural failure tests of the girders subjected to cyclic loading are carried out. For the failure analysis of the girders, the so-called volume control method is applied to finite element analysis of the precast PSC hollow box slab girders discretized using multi-layered shell elements. The analytical results by the volume control method is verified by comparing with test results.