To study the creep properties of the adhesive of carbon fiber reinforced polymer (CFRP)-steel interface

long-term loading tests of CFRP-steel double-lap specimens were carried out under different tensile loads

and the strain distribution law of CFRP and its changing characteristics with loading time were analyzed. Based on the characteristics of the Burgers model and the time-varying law of the shear strain of adhesive layer

a solving method for each parameter in the model was given. According to the experimental data

the expressions of the parameters in the Burgers model and the Findley power law equation were obtained. Results show that under the action of long-term interfacial shear stress

the adhesive of CFRP-steel interface had creep deformation

and the strain of CFRP decreased nonlinearly from loading end to fixed end

which increased with the increase of loading time and the increasing rate decreased gradually. The higher the value of interfacial nominal shear stress was

the larger the creep deformation of adhesive was

and the more the strain of CFRP increased. In the Burgers model

parameters ηM and GK were both linear functions of shear stress τ

and parameter ηK was a quadratic function of shear stress τ. In the Findley power law equation

parameter m was a linear function of shear stress τ

and parameter n was a quadratic function of shear stress τ. The root mean square errors of the Burgers model and the Findley power law equation were small

and both models could predict the creep deformation of the adhesive. When the interfacial shear stress τ was high

the creep deformation predicted by the Burgers model was better than that predicted by the Findley power law equation.