With the increasing hub height of wind turbines

traditional uniform-tapered conical towers face challenges in cost-effectiveness and structural stability. Assembled hybrid tower structures incorporating conical-cylindrical transition segments present a potential solution to these issues. However

the abrupt cross-sectional changes and stress concentrations at transition segments may lead to material plastic deformation and joint detach under extreme loading conditions. This study investigates a 150 m onshore wind turbine hybrid tower project

establishing a integral finite element model of the assembled hybrid tower and a sub-model of the conical-cylindrical transition segment using ABAQUS software. The research focuses on analyzing the nonlinear mechanical behaviors of critical components

specifically concrete tower segments

reinforcement bars

and curved bolt connectors in transition zones under ultimate load conditions

as well as the nonlinear contact stress states at transverse and longitudinal joints. The results demonstrate significant stress abrupt changes at cross-sections within the transition zone

with decreasing bending bearing capacity coefficients observed in lower transition segments. Under ultimate loads

transverse joint disengagement occurs with a maximum disengaged cross-sectional area ratio of 40.6%. Concrete at disengaged joint edges exhibits notable plastic characteristics

showing a maximum tensile damage factors up to 0.689 in localized regions. The ultimate load factor for the transition segment was determined to be 1.286. This study recommends implementing enhanced measures to improve the safety factor in conical-cylindrical transition segments during tower design.