• Advances in Computational Design
• /
• v.4 no.3
• /
• pp.223-238
• /
• 2019

This study investigated the ultimate lateral load capacity of shear walls constructed with several types of structural foam sheathing. Sixteen tests were conducted and the results were compared to the published design values commutated by the manufactures for each test series. The sheathing products included 12.7 mm (1/2 in) SI-Strong, 25.4 mm (1 in) SI-Strong, 12.7 mm (1/2 in) R-Max Thermasheath, and 2 mm (0.078 in) ThermoPly Green. The structural foam sheathing was attached per the manufacturers' specification to one side of the wood frame for each wall tested. Standard 12.7 mm (1/2 in) gypsum wallboard was screwed to the opposite side of the frame. Simpson HDQ8 tie-down anchors were screwed to the terminal studs at each end of the wall and anchored to the base of the testing apparatus. Both monotonic and cyclic testing following ASTM E564 and ASTM E2126, respectively, were considered. Results from the monotonic tests showed an 11 to 27 percent smaller capacity when compared to the published design values. Likewise, the test results from the cyclic tests showed a 24 to 45 percent smaller capacity than the published design values and did not meet the seismic performance design criteria computation.

• Computers and Concrete
• /
• v.17 no.3
• /
• pp.353-386
• /
• 2016

Realistic assessment of the performance of reinforced concrete structural members like columns is needed for designing new structures or maintenance of the existing structural members. This assessment requires analytical capability of employing proper material models and cyclic rules and considering various load and displacement patterns. A computer application was developed to analyze the non-linear, cyclic flexural performance of reinforced concrete structural members under various types of loading paths including non-sequential variations in axial load and bi-axial cyclic load or displacement. Different monotonic material models as well as hysteresis rules, were implemented in a fiber-based moment-curvature and in turn force-deflection analysis, using proper assumptions on curvature distribution along the member, as in plastic-hinge models. Performance of the program was verified against analytical results by others, and accuracy of the analytical process and the implemented models were evaluated in comparison to the experimental results. The computer application can be used to predict the response of a member with an arbitrary cross section and various type of lateral and longitudinal reinforcement under different combinations of loading patterns in axial and bi-axial directions. On the other hand, the application can be used to examine analytical models and methods using proper experimental data.

• Journal of Korean Association for Spatial Structures
• /
• v.24 no.1
• /
• pp.73-80
• /
• 2024

Non-uniform reinforced concrete brace facade systems are newly considered to improve seismic performance of reinforced concrete frame buildings under lateral load. For normal and high strength concrete of 30MPa, 80MPa, and 120MPa, the cross-sections of reinforced concrete brace facade systems were designed as different size with same amount of reinforcements. The strengthened frame systems were analyzed by a non-linear two-dimensional finite element technique which was considering material non-linearities of concrete and reinforcing bars under monotonic and cyclic loadings. From the study of non-linear analysis of the systems, therefore, it was provided that the proposed braced facade systems were reliable to improve laterally load-carrying capacity and minimize damages of concrete members through comparisons of load-displacement curves, crack patterns, and stress distributions of reinforcing bars predicted by current non-linear finite element analysis of frame specimens.

• Steel and Composite Structures
• /
• v.48 no.5
• /
• pp.565-582
• /
• 2023

The present research reports the application of engineered cementitious composites (ECC) as an alternative to conventional concrete to improve the seismic behavior of short columns. Experimental and finite element investigation was conducted by testing five reinforced engineered cementitious composite (RECC) concrete columns (half-scale specimens) and one control reinforced concrete (RC) specimen for different shear-span and transverse reinforcement ratios under cyclic lateral loads. RECC specimens with higher shear-span and transverse reinforcement ratios demonstrated a significant effect on the column lateral load behavior by improving ductility (>5), energy dissipation capacity (1.2 to 4.1 times RC specimen), gradual strength degradation (ultimate drift >3.4%), and altering the failure mode. The self-confinement effect of ECC fibers maintained the integrity in the post-peak region and reserved the transmission of stress through fibers without noticeable degradation in strength. Finite element modeling of RECC specimens under monotonic incremental loads was carried out by adopting simplified constitutive material models. It was apprehended that the model simulated the global response (strength and stiffness) and damage crack patterns reasonably well.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.05a
• /
• pp.520-523
• /
• 2004

The finite element method(FEM) models were developed for the reinforced concrete flexural walls and analysed under constant axial and monotonic lateral load using ABAQUS. The major objective of the present study is to determine if the ABAQUS finite element program can be used to accurately model the post-cracked mode of failure in plastic regions of walls, and, if so, to develop practical failure criteria in the plastic range of the material response. The research comprises constitutive models to represent behavior of the materials that compose a wall on the basis of experimental data, development of techniques that are appropriate for analysis of reinforced concrete structures, verification, and calibration of the global model for reinforced concrete walls of increasing complexity. Results from the analyses of these FEM models offers significant insight into the flexural behavior of benchmark data.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1999.04a
• /
• pp.501-506
• /
• 1999

The purpose of this study is to experimentally investigate the strength and ductility of reinforced high strength concrete columns under uniaxial load and several test variables. To do this, we have conducted tests on thirteen 20$\times$20$\times$60cm specimens with 8 and 12 longitudinal steel bars subjected to monotonic uniaxial compression. The main variables considered in this test are the configuration of ties, the space the ties, the diameter of ties and yield strength of ties. The results indicate that the strength and the ductility of reinforced high strength concrete columns have been influenced on these variables except yield strength of ties. Judging from test results, real stress of ties at peak concrete stress is suitable variable than yield strength of ties for estimation of the strength gain factor(Ks).

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.11a
• /
• pp.429-432
• /
• 2004

This paper discussed finite element method(FEM) models of the reinforced concrete rectangular shear walls with opening configuration and analysed under constant axial and monotonic lateral load using ABAQUS. The research comprises constitutive models to represent behavior of the materials that compose a wall on the basis of experimental data, development of techniques that are appropriate for analysis of reinforced concrete structures, verification, and calibration of the global model for reinforced concrete shear walls of increasing complexity. Results from the analyses of these FEM models offers significant insight into the flexural behavior of benchmark data.

• KIEAE Journal
• /
• v.7 no.6
• /
• pp.119-126
• /
• 2007

In the field of composite structures, the use of carbon tube for the confinement of concrete has been arisen since 1990's. However, experimental and analytical studies were limited to those of reinforced concrete and concrete filled steel tube. The carbon tube provides excellent confinement capabilities for concrete cores, enhancing compressive strength and ductility of concrete significantly. The carbon tube has high tensile strength, light weight, corrosion immunity and high fatigue strength properties. Since carbon fiber is an anisotropic material, carbon tube could be optimized by adjusting the fiber orientation, thickness and the number of different layers. In this study, both experimental and analytical studies of axial and lateral behavior of full-scale CFCT (Concrete Filled Carbon Tube) columns subjected to monotonic axial load were carried out using Drucker-Prager theory. And, based on comparison results between experiment results and analytical results, k factor estimation was proposed for effective analysis.

• Structural Engineering and Mechanics
• /
• v.66 no.4
• /
• pp.531-542
• /
• 2018

In this paper an analytical model in a closed form able to reproduce the monotonic flexural response of external RC beam-column joints with smooth rebars is presented. The column is subjected to a constant vertical load and the beam to a monotonically increasing lateral force applied at the tip. The model is based on the flexural behavior of the beam and the column determined adopting a concentrated plasticity hinge model including slippage of the main reinforcing bars of the beam. A simplified bilinear moment-axial force domain is assumed to derive the ultimate moment associated with the design axial force. For the joint, a simple truss model is adopted to predict shear strength and panel distortion. Experimental data recently given in the literature referring to the load-deflection response of external RC joints with smooth rebars are utilized to validate the model, showing good agreement. Finally, the proposed model can be considered a useful instrument for preliminary static verification of existing external RC beam-column joints with smooth rebars for both strength and ductility verification.

• Structural Engineering and Mechanics
• /
• v.59 no.2
• /
• pp.291-312
• /
• 2016

Seismic performance evaluation of shear wall is essential as it is the major lateral load resisting member of a structure. The ultimate load and ultimate drift of the shear wall are the two most important parameters which need to be assessed experimentally and verified analytically. This paper comprises the results of monotonic tests, quasi-static cyclic tests and shake-table tests carried out on a midrise shear wall. The shear wall considered for the study is 1:5 scaled model of the shear wall of the internal structure of a reactor building. The analytical simulation of these tests is carried out using micro and macro modeling of the shear wall. This paper mainly consists of modification in the hysteretic macro model, developed for RC structural walls by Lestuzzi and Badoux in 2003. This modification is made by considering the stiffness degradation effect observed from the tests carried out and this modified model is then used for nonlinear dynamic analysis of the shear wall. The outcome of the paper gives the variation of the capacity, the failure patterns and the performance levels of the shear walls in all three types of tests. The change in the stiffness and the damping of the wall due to increased damage and cracking when subjected to seismic excitation is also highlighted in the paper.