The cumulative damage of the reinforced concrete (RC) crane girders occurred by
overload, fatigue and other reasons in service may deteriorate the safety of RC crane girders seriously,
so it is necessary to analyze the damage mechanism and rationally reinforce them in good time. In this
paper, RC crane girder strengthened with CFRP strips is taken as a target, and the mechanical
performance degradation under fatigue load is studied. According to the basic theory of continuum
damage mechanics, a damage variable is defined by flexural rigidity, and fatigue- cumulative damage
model, which describes the process of damage and fracture, is established. The variation law of
cumulative damage of RC crane girders strengthened with FRP strips under crane load is discussed,
and the failure patterns such as concrete cracking, debonding between CFRP strips and concrete, yield
of steel bars etc., are studied. The criterion which can be used to estimate the cumulative damage
degree of strengthened RC crane girders is proposed. Finally, the evolution of the fatigue damage in
the RC crane girders strengthened with CFRP strips is numerically simulated, and the results show
that the proposed model can correctly describe the damage and failure process of strengthened RC
crane girders. The research will provide a reference for the damage analysis and reinforcement of RC
crane girders strengthened with CFRP strips.
Performance of Steel I-Beams Strengthened by Fastening Hybrid FRP
Strips
