Short-Term Performance of New Composite Anchorage with Multiple CFRP Tendons

Acknowledgments

Notation

A_pk

effective cross-sectional area of single CFRP tendon;

a

inner radius of the cylinder;

b

outer radius of the cylinder;

D₀

outer diameter of the steel sleeve;

D₁

inner diameter of the steel sleeve at free end;

D₂

outer diameter of the aluminum tube at free end;

D₁(x)

inner diameter of the steel sleeve at any longitudinal position;

D₂(x)

inner diameter of the clamps at any longitudinal position;

E

elastic modulus of the cylinder;

E_b

elastic modulus of the steel sleeve;

F_ptk

theoretical ultimate tensile strength of the anchorage;

F₁

radial pressure at Interface I;

F₂

radial pressure at Interface II;

f_ptk

tensile strength of a single CFRP tendon;

f₂

friction force at Interface II;

l

displacement of the clamp along the x-axis under preloading force and external loads;

n

number of CFRP tendons in the anchorage;

q

internal pressure of the thick-walled cylinder;

r

distance from a point on the cylinder cross section to the center of the section;

u

radial displacement from a point on the cylinder cross section to the center of the section;

ν

Poisson’s ratio of the cylinder;

ν_b

Poisson’s ratio of the steel sleeve;

α

cone angle of the outer surface of the aluminum tube;

β

cone angle of the outer surface of the steel clamps;

Δ_b(x)

radial displacement of the steel sleeve at any point in the x-axis;

Δ_g(x)

total radial displacement of the aluminum tube, bonding medium, and CFRP tendons;

δ₂

longitudinal slip of the aluminum tube relative to the clamps;

${\epsilon }_{\theta }$

circumferential strain from a point on the cylinder cross section to the center of the section;

${\epsilon }_0(x)$

circumferential strain at the outer surface of the steel sleeve;

η_a

anchoring efficiency coefficient of the anchorage;

μ₂

friction coefficient between the clamps and the aluminum tube;

σ₁(x)

radial uniform compressive stress at Interface I; and

σ₂(x)

radial uniform compressive stress at Interface II.

References