Influence of CFRP local reinforcement on hysteretic and buckling characteristics of corroded wind turbine tower

Abstract:

The offshore wind turbine tower has been used in the marine corrosive environment for a long time. The tower structure in marine corrosive environment is prone to local buckling and collapse under the impact of wind, wave, earthquake and other reciprocating loads. In this paper, carbon fiber reinforced polymer (CFRP) is proposed for local reinforcement of the corroded wind turbine tower. The single shear test and numerical simulation study of CFRP steel composite structure are carried out. On the basis of simple shear test, the hysteretic performance of corroded wind turbine tower strengthened with CFRP is studied using ABAQUS software and python. Structural damages and energy consumption mechanisms under four corrosion conditions and six reinforcement conditions are compared. Results show that the high temperature environment softens the contact between CFRP and steel, which reduces the bearing capacity of CFRP steel composite structures. The fiber fracture of CFRP steel composite structure occurs earlier than the damage of adhesive layer under tensile force. The contact relationship of CFRP steel can be simplified as the “Tie” in numerical simulation. Under the cyclic load, the corroded tower structure shows early buckling, the proportion of material plastic energy consumption decreases and the proportion of “buckling hinge” energy consumption increases. After CFRP strengthening, the buckling of the structure can be delayed, the plastic region of the material can be expanded and the overall energy dissipation capacity of the structure can be improved. In order to prevent the sudden damage of the structure when the number of CFRP strengthening layers is small, attention should be paid to the structural ductility change during strengthening.