Performance of steel brace members

Technical Abstract

Analytical and experimental studies have been conducted in this research to study the inelastic steel brace member behaviour under cyclic load.

In the analytical study, three types of steel brace model were reviewed. They were the purely theoretical model, the phenomenological model, and the refined physical theory model. Their advantages and disadvantages were also identified.

A 150 UC 30 was chosen as a representative universal column section. Three 150 UC 30 brace specimens were tested with slenderness ratios of 40, 60 and 80. The overall and inelastic behaviour of the specimens under cyclic load were studied.

The refined physical theory brace model from Ikeda was used to predict the axial force versus axial displacement relationships of the test specimens. The analytical results showed good agreement with the test results for relatively low axial displacement amplitudes. The need to include the effect of tangent modulus history degradation and strain hardening into the available model was emphasised for large axial displacement amplitudes.