Seismic Behavior of Concrete-Encased Composite Beam-Columns with T-Shaped Steel Section
Dr. Cheng-Chih Chen
|關鍵字:||T字型鋼骨斷面;包覆型鋼骨鋼筋混凝土;梁柱;軸力-彎矩強度;韌性;composite;beam-column;T-shaped steel section;ductility|
SRC beam-columns with T-shaped steel section can be arranged to connect the beams for the architectural reason. However, the eccentricity and unsymmetricity of the T-shaped steel section on the x-axis will lead to the difference of flexural strength and ductility as well as the seismic behavior in the positive and the negative moment directions when the column subjects to a cyclic lateral load. Therefore, seismic behavior of SRC beam-columns with T-shaped steel section must be investigated. Twenty-eight concrete-encased T-shaped steel section composite beam-columns were tested under constant axial load and cyclic lateral load. The variables of the specimens included the number of longitudinal bars, hoop spacing, presence of the crosstie, the magnitude of the axial load, and the slenderness ratio. The test results showed that the flexural strengths of the SRC columns in the positive and the negative moment directions about the x-axis, with respective to the unsymmetrical steel section, can be achieved to have equal amount by adding the additional longitudinal bars. Designing the hoop spacing according to the ACI seismic code and using crosstie can enhance the ductility of the SRC columns. The flexural strength of the SRC columns with high slenderness ratio was lower than those with low slenderness ratio. The flexural strength calculated according to ACI code expressions can predict the flexural strength of the tested SRC columns reasonably and conservatively with 83% accuracy. The moment magnifier also can be forecasted perfectly with 99% accuracy.
|Appears in Collections:||Thesis|