Experimental investigation on the friction behavior of CFRP plate in contact with sandblasted steel plate

Abstract

The coefficient of static friction (COSF) between the steel plate and carbon fiber-reinforced polymer (CFRP) plate is a significant impact parameter for the design of mechanical anchors. In this study, the friction behavior and wear mechanism between the sandblasted steel plate and CFRP plate with different surface treatment methods under various normal pressures and anchor lengths were investigated through the planar clamping anchor. In order to improve the surface roughness level, the surface of CFRP plate was treated by galling or sand coating. The results indicate that the COSF of the galling surface ranged of 0.28–0.30 corresponding to various parameters, while that of the sand coating surface changed between 0.27 and 0.35. Although the COSF could be obviously enhanced by the surface sand coating, the discreteness of COSF was large and the relaxation of bolt preload was severe. Moreover, the COSF presented a decreasing trend when the normal pressure exceeded 33 MPa, whereas that kept almost constant with the increase of anchor length. The failure mode changed from slip failure to incomplete or complete burst failure with increasing normal pressure and anchor length. The friction failure process of CFRP plate was dominated by ploughing and wear, which caused changes of the tensile load and bolt preload at different stages. The research in this paper contributes to providing guidance for the design of mechanical clamping anchors, especially for the clamping anchor with constant or variable curvature waveform.