Damage evolution and failure analysis of the advanced transition segment behavior of wind turbine tower

The complexity of reinforcement and consequent corrosion of concrete have been technical issues of the transition segments of the hybrid wind turbine tower. A novel concrete transition segment using prestressed ultra-high performance concrete (UHPC) that does not necessitate ordinary reinforcement is applied to a 4.8 MW H160 prestressed hybrid wind turbine tower. The mechanical behaviors of the transition segments only with reinforced concrete segment (T-C80RC) and the UHC140 segment without ordinary reinforcement (T-UHC140) are investigated using three-dimensional finite element models. The damage evolutions in the transition segments under overestimated design load are also reported. A structural state monitoring method based on the Mann-Kendall mutation criterion for the strain energy (SSMM-MK) is proposed to evaluate the structural state and determine the failure load of transition segments. Based on the identical sectional dimensions of the concrete segments, the comparative study demonstrates that using UHPC in T-UHC140 results in a decrease in plastic damage, an improvement in overall mechanical performance and consequently increases the ultimate bearing capacity to 2.1 times that of the reinforced concrete segment. The SSMM-MK method provides an innovative and effective way of structural state analysis by combining the finite element model and the evaluation method proposed can effectively evaluate the structural state of the transition segment.