scholarly journals Behavior of Structural Concrete Frames with Hybrid Reinforcement under Cyclic Loading

2021 ◽  
Vol 15 (57) ◽  
pp. 70-81
Author(s):  
Asmaa Sobhy ◽  
Louay Aboul Nour ◽  
Hilal Hassan ◽  
Alaaeldin Elsisi
Keyword(s):  
Energy Dissipation ◽  
Cyclic Loading ◽  
Joint Model ◽  
Fiber Reinforced Polymer ◽  
Longitudinal Reinforcement ◽  
Fiber Reinforced ◽  
Joint Models ◽  
Reversed Cyclic Loading ◽  
Reinforced Polymer ◽  
Reversed Cyclic

A substantial amount of work was carried out on the use of fiber-reinforced polymer (FRP) in reinforcing concrete structural elements, which demonstrated considerable inelasticity or deformity through monotonous and fatigue loads. Even so, the action of FRP bars in FRP-RC columns and frame structures has not yet been studied during reversed cyclic loading. In this research, reversed cyclic loading was conducted on three beam-column joint models using the finite element method with ANSYS software. The first model was for a joint designed with steel rebar for both the longitudinal reinforcement and stirrups. Glass fiber reinforced polymer (GFRP) rebar was used to reinforced the second joint model for both longitudinal reinforcement and steel stirrups, and the third joint model was designed with hybrid steel/GFRP reinforcement for the longitudinal reinforcement and steel stirrups. The performance of the three models under reversed cyclic loading, such as load vs. story drift and energy dissipation capacity, were compared. The GFRP-reinforced model displayed a predominantly elastic activity up to failure. Although its energy dissipation was weak, its performance in terms of total storey drift demand was satisfactory.

Experimental study of precast beam-to-column joints with steel connectors under cyclic loading

2020 ◽  
Vol 23 (13) ◽  
pp. 2822-2834
Author(s):  
Xian Rong ◽  
Hongwei Yang ◽  
Jianxin Zhang
Keyword(s):  
Energy Dissipation ◽  
Cyclic Loading ◽  
Load Capacity ◽  
Precast Concrete ◽  
Displacement Ductility ◽  
Reversed Cyclic Loading ◽  
Column Joint ◽  
Energy Dissipation Capacity ◽  
Reversed Cyclic ◽  
The Web

This article investigated the seismic performance of a new type of precast concrete beam-to-column joint with a steel connector for easy construction. Five interior beam-to-column joints, four precast concrete specimens, and one monolithic joint were tested under reversed cyclic loading. The main variables were the embedded H-beam length, web plate or stiffening rib usage, and concrete usage in the connection part. The load–displacement hysteresis curves were recorded during the test, and the behavior was investigated based on displacement ductility, deformability, skeleton curves, stiffness degradation, and energy dissipation capacity. The results showed that the proposed beam-to-column joint with the web plate in the steel connector exhibited satisfactory behavior in terms of ductility, load capacity, and energy dissipation capacity under reversed cyclic loading, and the performance was ductile because of the yielding of the web plate. Therefore, the proposed joint with the web plate could be used in high seismic regions. The proposed joint without the web plate exhibited similar behavior to the monolithic specimen, indicating that this joint could be used in low or moderate seismic zones. Furthermore, the utilization of the web plate was vital to the performance of this system.

Seismic performance of FRP-reinforced concrete-filled thin-walled steel tube considering local buckling

2018 ◽  
Vol 37 (9) ◽  
pp. 592-608 ◽  
Author(s):  
CY Zhu ◽  
YH Zhao ◽  
L Sun
Keyword(s):  
Energy Dissipation ◽  
Seismic Performance ◽  
Local Buckling ◽  
Steel Tube ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Thin Walled

The objective of this study is to investigate the seismic performance of fiber-reinforced polymer-reinforced concrete-filled thin-walled steel tube (CFTST). Twelve specimens with different fiber-reinforced polymer types (glass fiber-reinforced polymer and carbon fiber-reinforced polymer) and reinforcing modes were tested under constant axially compressive load and cyclic lateral load. The failure mode and lateral load versus displacement relationship for each specimen were recorded during testing. The strength, ductility, and energy dissipation capacity were analyzed accordingly. Further, a stress–strain relationship and a restoring force model of the fiber-reinforced polymer confining steel tube with local buckling were proposed. A hysteretic model for the fiber-reinforced polymer-reinforced CFTST was developed subsequently. The results indicate that the seismic performance of fiber-reinforced polymer-reinforced CFTST can be effectively improved by optimizing the fiber-reinforced polymer type and corresponding reinforcing scheme. Carbon fiber-reinforced polymer and glass fiber-reinforced polymer are suitable materials for the confinement and bending reinforcement of the column, respectively. The modeling results show the energy imported into the column is mainly dissipated by the thin-walled steel tube. The energy dissipation proportion of the steel tube, concrete core, and longitudinal fiber-reinforced polymer are >80%, 10%–20%, and <8%, respectively. The energy dissipation value of the steel tube can be improved more than 40% after effectively restraining the local buckling.

scholarly journals Experimental Study of the Probabilistic Fatigue Residual Strength of a Carbon Fiber-Reinforced Polymer Matrix Composite

2020 ◽  
Vol 4 (4) ◽  
pp. 173
Author(s):  
Xiang-Fa Wu ◽  
Oksana Zholobko
Keyword(s):  
Experimental Study ◽  
Tensile Strength ◽  
Carbon Fiber ◽  
Cyclic Loading ◽  
Polymer Matrix ◽  
Residual Strength ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

Degradation of the mechanical properties of fiber-reinforced polymer matrix composites (PMCs) subjected to cyclic loading is crucial to the long-term load-carrying capability of PMC structures in practice. This paper reports the experimental study of fatigue residual tensile strength and its probabilistic distribution in a carbon fiber-reinforced PMC laminate made of unidirectional (UD) carbon-fiber/epoxy prepregs (Hexcel T2G190/F263) with the ply layup [0/±45/90]S after certain cycles of cyclic loading. The residual tensile strengths of the PMC laminates after cyclic loading of 1 (quasistatic), 2000, and 10,000 cycles were determined. Statistical analysis of the experimental data shows that the fatigue residual tensile strength of the PMC laminate follows a two-parameter Weibull distribution model with the credibility ≥ 95%. With increasing fatigue cycles, the mean value of the fatigue residual strength of the PMC specimens decreased while its deviation increased. A free-edge stress model is further adopted to explain the fatigue failure initiation of the composite laminate. The present experimental study is valuable for understanding the fatigue durability of PMC laminates as well as reliable design and performance prediction of composite structures.

scholarly journals Experimental Studies on Seismic Performance of Precast Steel Reinforced Concrete Frame and Connections

2015 ◽  
pp. 349-357
Author(s):  
Xiang Hu ◽  
Weichen Xue ◽  
Yanbo Sun ◽  
Chenguang Li
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Cyclic Loading ◽  
Seismic Performance ◽  
Experimental Studies ◽  
Frame Structures ◽  
Seismic Zone ◽  
Reversed Cyclic Loading ◽  
Steel Reinforced Concrete ◽  
Reversed Cyclic

A new type of precast steel reinforced concrete (PSRC) frame, which were composed of composite steel reinforced concrete (CSRC) beam, PSRC column and cast-in-situ (CIS) joint, were proposed in this paper. The assemble technique used in the ordinary steel structures were adopted in PSRC frames to improve the construction efficiency. The seismic performance of PSRC frame structures was investigated based on the test results of connections and frame. Firstly, full-scale internal connection specimens, including a CIS connection specimen RCJ-1 and a PSRC connection specimen PCJ-1, were tested under low reversed cyclic loading. Results revealed that both the specimens RCJ-1 and PCJ-1 exhibited similar performance in terms of loading capacity, stiffness degradation and energy dissipation. The ductility of specimen PCJ-1 was about 3.81, which was a little lower than the specimen RCJ-1. Then, a 1/3-scale PSRC frame structure specimen, namely PCF-1, was tested under low reversed cyclic loading. Results showed that the PSRC frame specimen PCF-1 was failed in mixed failure mechanism, which provide good energy dissipation capacity. The ductility coefficient of PCF-1 was about 3.45 indicating that the PCF-1 behaved in ductility manner. The results of this investigation could enrich the data available documenting the behavior of PSRC frame, and contribute to enlarge the application of PSRC frame structures in seismic zone.

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