Concrete-Filled Multicellular Steel-Tube Shear Walls with FRP Tubes Embedded in CFST: Concept and Seismic Performance

Acknowledgments

Notation

A_c

cross-sectional areas of concrete, mm²;

A_s

cross-sectional areas of steel, mm²;

b

width of the shear wall, mm;

d

length of the diagonally arranged LVDTs, mm;

E

dissipated energy of each hysteresis loop, kN · m;

E_d

accumulated dissipated energy during the whole loading process, kN · m;

F

lateral load applied to the specimen, kN;

F_f

lateral load at the failure point, kN;

$F_i^1$

peak loads obtained in the first cycle in ith lateral displacement level, kN;

$F_i^2$

peak loads obtained in the second cycle in ith lateral displacement level, kN;

F_p

lateral load at the peak point, kN;

F_pi

local peak load in the ith circle lateral displacement, kN;

F_y

lateral load at the yielding point, kN;

f_c

compressive prism strength of concrete, MPa;

f_cu

compressive cube strength of concrete, MPa;

f_y

yielding strength of steel, MPa;

H

height of loading point to the top surface of the foundation beam, mm;

K₀

initial stiffness, kN/mm;

K_i

stiffness in the ith lateral displacement level, kN/mm;

K_p

stiffness at the peak point, kN/mm;

K_u

stiffness at the ultimate state, kN/mm;

K_y

stiffness at the yielding point, kN/mm;

N

design axial force applied to the specimen, kN;

n

design axial force ratio;

Δ

lateral displacement of the specimen, mm;

Δ_f

lateral displacement at the failure point, mm;

Δ_p

lateral displacement at the peak point, mm;

Δ_pi

lateral displacement at the peak point of the ith lateral displacement level, mm;

Δ_s

shear displacement of the specimen, mm;

Δ_u

lateral displacement at the ultimate state, mm;

Δ_y

lateral displacement at the yielding point, mm;

δ₁

displacement measured by the LVDT5, mm;

δ₂

displacement measured by the LVDT6, mm;

ɛ_a

axial strain, %;

ɛ_h

hoop strain, %;

θ

drift ratio, %;

θ_c

drift ratio at the cracking point, %;

θ_f

drift ratio at the failure point, %;

θ_p

drift ratio at the peak point, %;

θ_y

drift ratio at the yield point, %;

θ_μ

drift ratio at ultimate state, %;

λ_i

strength degradation coefficient in the ith lateral displacement level; and

μ

ductility coefficient.

References