CFRP Strengthening of Steel Plates Subjected to Mixed Mode Fatigue Loading

Abstract

In this thesis the current knowledge of tension (mode-I) fatigue strengthening using carbon fibre reinforced polymer (CFRP) composites is extended to the case of mixed-mode (I+II) fatigue loading conditions. The fatigue behaviour and the fatigue performance of the CFRP strengthening systems were investigated experimentally under the effect of the initial crack orientation, crack length ratio, mechanical properties of the composite material, and the fibre orientation. Furthermore, 3D Finite Element analyses were performed on the test specimens and the influence of the geometric nonlinearity, orthotropy of the CFRP composite, and the out-of-plane bending in asymmetric repair were highlighted.