Cyclic Behavior of Square CFST Columns-Based Joint

Table 4

Main performance points.

Specimen No.	Loading direction	Ke (kN/mm)	Py (kN)	△y (mm)	Pp (kN)	△p (mm)	Pmax (kN)	△max (mm)
No. 1	Positive	17	184	16.3	204	20.6	231	43.7
	Negative	13	−206	−21.6	−218	−23.6	−223	−45.0
No. 2	Positive	18	296	21.9	311	23.7	345	60.6
	Negative	17	−316	−27.2	−320	−28.1	−382	−68.9
No. 3	Positive	14	182	22.6	188	25.5	222	52.8
	Negative	11	−181	−26.4	−197	−34.9	−229	−53.4
No. 4	Positive	13	244	32.8	254	34.1	273	84.4
	Negative	13	−220	−27.1	−247	−34.5	−269	−75.6
No. 5	Positive	16	217	12.8	284	27.8	306	30.0
	Negative	11	−239	−24.4	−254	−29.4	−271	−30.4
No. 6	Positive	21	225	15.5	270	24.3	299	48.9
	Negative	14	−275	−27.3	−290	−31.6	−298	−34.6

Note: K_e is initial stiffness, P_y is yield loading force, P_p is plastic loading force, P_max is maximum loading force, △_y is yield displacement, △_p is plastic displacement, and △_max is displacement of P_max.