Hysteresis analysis of the concentric braced frame Abaqus

Product Overview

In this example, we simulate the cyclic behavior of a special concentrically braced frame (CBF) using the Abaqus software.

The structural system consists of beam, column, brace, gusset plate, and double-angle beam-to-column connections.

The main structural members consist of an IPE270 beam, IPB120 columns, and UNP60 brace members. The beam-to-column connections are modeled using double-angle connections with L100 × 100 × 10 mm angle sections.

The brace members are connected to the frame through gusset plates. The gusset plates include 250 × 250 × 12 mm plates at the middle connection and 280 × 280 × 8 mm plates at the corner connections.

Cyclic Loading

The CBF is subjected to quasi-static cyclic lateral loading to reproduce the loading procedure used in the experimental study. The loading is displacement-controlled and consists of repeated positive and negative lateral displacement cycles.

The loading history is defined in Abaqus according to the loading protocol used in the experimental study.

Comparison of Abaqus and Experimental Results

In this picture, the force-drift hysteresis diagram obtained from the Abaqus software is compared with the experimental results.

This comparison is used to evaluate the accuracy of the numerical model and its ability to reproduce the experimental response of the concentric braced frame.

Brace Buckling and Yielding

The brace members play a major role in the nonlinear response of the concentrically braced frame. During cyclic loading, the braces are subjected to alternating tension and compression, resulting in yielding and out-of-plane buckling.

As the lateral displacement increases, the brace first develops axial yielding. Under subsequent compression loading, the brace undergoes out-of-plane buckling, producing significant nonlinear deformation.

The buckling of the brace causes a reduction in the lateral stiffness and contributes to the characteristic hysteretic response of the CBF. The deformation progressively increases as the cyclic loading continues.

The Abaqus simulation is used to reproduce this buckling behavior and to investigate the development of nonlinear deformation in the brace members during cyclic loading.

Gusset Plate Behavior

The gusset plates provide the connection between the brace members and the surrounding steel frame. Their behavior has an important influence on the nonlinear response of the concentrically braced frame during cyclic loading.

As the brace members undergo tension, compression, yielding, and out-of-plane buckling, significant stresses and plastic deformation develop in the gusset plate regions.

The Abaqus model is used to investigate the stress and deformation behavior of the gusset plates during cyclic loading. The development of plastic deformation and yielding around the brace connections can be observed as the lateral displacement increases.

The numerical deformation and stress patterns can also be compared with the behavior observed in the experimental CBF specimen, providing an additional means of evaluating the numerical model.

Validation

This project has been validated, which means that the results obtained from the Abaqus software are similar to the results reported in the article.

In other words, this project is based on the reference article and the numerical model has been developed to reproduce the experimental response of the concentric braced frame.

What You Will Learn

• How to model a concentric braced frame in Abaqus.
• How to model the beam.
• How to model the column.
• How to model the brace.
• How to model the gusset plate.
• How to model the angle connection.
• How to define the material properties of the structural components.
• How to assemble the complete model.
• How to define the boundary conditions.
• How to apply cyclic loading to the model.
• How to define the cyclic loading amplitude.
• How to obtain the hysteresis diagram from Abaqus.
• How to compare the Abaqus results with experimental results.
• How to investigate the structural response under cyclic loading.
• How to validate the numerical model using the reference article.

Key Features

• Concentric braced frame modeling in Abaqus.
• Beam and column modeling.
• Brace modeling.
• Gusset plate modeling.
• Angle connection modeling.
• Cyclic loading analysis.
• Cyclic loading amplitude definition.
• Hysteresis diagram obtained from Abaqus.
• Comparison between Abaqus and experimental results.
• Investigation of the structural response under cyclic loading.
• Validation against the reference article.
• Complete Abaqus CAE file.
• Abaqus INP file.
• Excel amplitude loading file.
• Excel results file.
• Reference research paper.
• Step-by-step video tutorial.

Reference

This project is based on the reference research article. The paper is included with the project files and can be used to review the experimental model, loading protocol, and reported results.