Theoretical Study of Self-Balancing Pretensioned CFRP Cable Braces for Seismic Resistance of Buildings

Data Availability Statement

Acknowledgments

Notation

$A_{c\mathrm{\_}CB3600}$, $A_{c\mathrm{\_}CB4700}$

composite areas of CB3600 and CB4700 cable braces, respectively;

A_g, N

gross area of the cross section and applied axial compressive load, respectively;

b and c

$\sqrt{1+{(h/L)}^2}$ and h/L, respectively;

b_f, d, D

width of flange, inner depth of the web, and overall depth of the beam, respectively;

C_my, C_mz, C_mLT

equivalent uniform moment factors;

D_slab

depth of the RCC slab;

E_HR, E_CB

modulus of elasticity of hot-rolled sections and CFRP cables in MPa, respectively;

f_cd

design stress under axial compression as governed by buckling;

f_cre, σ_s

expected critical stress and postyield strength in HR braces, respectively;

f_y, f_u, f_yw

yield, tensile strength, and the yield strength of the web;

h, L

story height and bay width, respectively;

I_zz, I_yy

second moment of area about major (zz) and minor (yy) axes, respectively;

L_yy

buckling length about the minor (yy) axis;

l_b

length of the brace;

M, V

applied moment and shear;

M_d,zz, M_d,yy

design bending strength about major (zz) and minor (yy) axes, respectively;

N_cr

Euler's buckling load;

N_cr,zz, N_cr,yy

Euler's buckling load about major (zz) and minor (yy) axes, respectively;

N_d

design compressive strength due to yielding;

N_db

design capacity under axial compression as governed by buckling;

N_db,yy, N_db,zz

design strength under axial compression as governed by buckling about minor (yy) and major (zz) axes, respectively;

P_s,b

ultimate compressive force in hot-rolled braces;

P_s,c

cable pretension force;

Q₁ and Q₂

applied lateral force in the top roof and first floor level, respectively;

${\displaystyle \frac{S_a}{g}}$, W

acceleration coefficient and seismic weight;

s, R_y

length of yield plateau under axial compression and over strength factor;

T

fundamental time period of the building;

TE_HR, TE_CB3600, and TE_CB4700

total strain energy capacity of HR, CB3600, and CB4700 braces, respectively;

t_f, t_w

thickness of the flange and web, respectively;

V_b

base shear;

V_s

shear-wave velocity;

Y_beam, Y_slab

centroid distance of the steel beam and RCC slab, respectively;

Z, I, R

zone factor, importance factor, and response reduction factor, respectively;

Z_pz, Z_py

plastic sectional modulus about major (zz) and minor (yy) axes, respectively;

Δ_zz, L_eff

maximum deflection in beam and effective length against buckling, respectively;

r, λ

radius of gyration and slenderness ratio of the brace, respectively;

λ_c

nondimensional effective slenderness ratio;

α, K_y, K_z, K_LT

imperfection factors;

$\sigma ,\epsilon$

axial stress and axial strain, respectively;

σ_exp, ${\epsilon }_{exp}$

expected strength and strain under axial compression in HR braces, respectively;

σ_ps, ${\epsilon }_{ps}$

permissible strength and permissible strain in CB braces, respectively;

${\sigma }_{ps\mathrm{\_}CB3600}$, ${\epsilon }_{ps\mathrm{\_}CB3600}$

permissible strength and permissible strain in CB3600 braces, respectively; and

${\sigma }_{ps\mathrm{\_}CB4700}$, ${\epsilon }_{ps\mathrm{\_}CB4700}$

permissible strength and permissible strain in CB4700 braces, respectively.

References