Zhuojin Pipe Fitting Co., LtdLateral Load-Bearing Capacity of Square Steel Tube Concrete Frame with Embedded Side-Opening Thin Steel Plate Shear Wall
Overview of the Study
This research by Wang Xiantie, Zhou Xuhong, Chu Zhaowen, Liu Lida, and He Bo, published in the Journal of Xi'an University of Architecture and Technology in 2017, investigates the lateral load-bearing capacity of a hybrid structural system that combines square steel tube concrete (SRC) frames with embedded thin steel plate shear walls (SPSWs) featuring side openings. The study combines pseudo-static experimental testing on a one-third scale single-bay two-story specimen with nonlinear finite element analysis using ABAQUS, and proposes a calculation model and formula for the lateral load-bearing capacity of this composite system.
Structural System Description
The hybrid system integrates three key structural elements: square steel tube concrete columns that provide high axial load capacity and ductility; a steel beam frame that provides lateral load resistance through flexural action; and a thin steel plate shear wall with side openings that provides additional lateral stiffness and strength through in-plane membrane action. The side openings in the shear wall are necessary for architectural and functional requirements such as doorways and windows, but they also introduce complexity in the load transfer mechanism and potential weak points in the structural system.
The side-opening thin steel plate shear wall operates through a combination of mechanisms: the solid portions of the steel plate develop diagonal tension and compression fields under lateral loading; the opening edges act as boundary elements that redistribute stresses; and the interaction between the steel plate and the surrounding concrete infill or frame members provides additional confinement and load path continuity. The connection details between the opening edge members and the boundary beams are critical to the overall performance of the system.
Experimental and Analytical Results
The pseudo-static test on the one-third scale specimen revealed that the hybrid system exhibits high lateral load-bearing capacity, high initial stiffness, and good ductility. The failure mechanism was characterized by yielding and local buckling of the steel plate shear wall, plastic hinge formation at the beam ends, and progressive deformation of the square steel tube concrete columns. The finite element analysis using ABAQUS with appropriate material constitutive models and failure criteria reproduced the experimental hysteresis curves and skeleton curves with good accuracy.
| Performance Indicator | Experimental Result | FEA Result | Proposed Formula Result |
|---|---|---|---|
| Peak lateral load | Baseline | Close agreement | Good agreement |
| Initial stiffness | Baseline | Close agreement | Good agreement |
| Ductility | High | High | N/A |
| Failure mode | Steel plate yielding and local buckling | Consistent with test | Consistent with test |
| Hysteresis behavior | Stable energy dissipation | Consistent | N/A |
The study also investigated the influence of different connection methods between the opening edge members and the boundary beams on the lateral load-bearing capacity. The connection details significantly affect the stress distribution around the opening, the load transfer path, and the overall deformation capacity of the shear wall. Rigid connections provide higher lateral load-bearing capacity but may lead to more brittle failure, while semi-rigid connections offer a better balance between strength and ductility.
Proposed Calculation Model
Based on the understanding of the load-bearing mechanism, the authors developed a calculation model for the lateral load-bearing capacity of the square steel tube concrete frame with embedded side-opening thin steel plate shear wall. The model considers the contributions of the steel plate shear wall through diagonal tension field action, the frame action of the steel beams and square steel tube concrete columns, and the interaction between the steel plate and the opening edge members. The proposed formula was validated against both experimental results and full-scale finite element model results, demonstrating good agreement.
The calculation model can be decomposed into three components: the lateral load resistance from the steel plate shear wall, which depends on the steel plate thickness, yield strength, and the effective height and width of the solid portions; the lateral load resistance from the frame action, which depends on the flexural capacity of the beams and the shear capacity of the columns; and the interaction effects between the steel plate and the frame, which include the restraint effect of the frame on the steel plate deformation and the load transfer through the opening edge connections.
Engineering Practice Implications
This hybrid structural system offers several advantages for practical engineering applications. The square steel tube concrete columns provide high axial load capacity and excellent ductility, making them suitable for high-rise buildings and structures subject to seismic loading. The thin steel plate shear wall provides high lateral stiffness and strength with minimal space occupancy, which is advantageous for buildings where floor area efficiency is critical. The side openings accommodate architectural requirements without significantly compromising the structural performance, provided that appropriate edge members and connection details are employed.
From a construction and quality control perspective, the fabrication of square steel tube concrete columns requires careful attention to the welding of the square steel tube segments, the placement of the concrete within the tube, and the connection between the tube and the structural steel beams. The steel plate shear wall requires precise fabrication to ensure flatness and dimensional accuracy, and the welding of the opening edge members must be performed with high-quality weld procedures to ensure full strength and ductility at the critical connection points.
Study Insights
This research contributes valuable knowledge to the design of hybrid structural systems that combine the advantages of steel tube concrete columns, steel frames, and steel plate shear walls. The proposed calculation formula provides a practical tool for engineers to estimate the lateral load-bearing capacity of this system during the preliminary design phase, and the experimental and analytical results provide confidence in the structural performance of the system under seismic loading. The study highlights the importance of connection details in determining the overall behavior of composite structural systems, and it underscores the value of combining experimental testing with nonlinear finite element analysis to develop reliable design methods.