2025 Volume 32 Issue 126 Pages 1-14
This paper proposes evaluation formulas for the number of cycles at the limit state in the plastic region of concrete-filled square steel tube (CFT) beam-columns under varying axial load. The limit state of the cyclic load is defined as the state where the shear force is reduced to 90% of the maximum load. The evaluation formulas for the number of cycles at the limit state are regression formulas obtained from previous test results, with the axial strain at the end of the column beam as the main factor. The prediction results using the proposed evaluation formula are almost in agreement with the experimental results for the number of cycles at the limit state in the plastic region.
