This study provides an insight of the nonlinear behavior of the Offshore Wind Turbine (OWT) structure using the distributed plasticity approach. The fiber section beam-column element is applied to construct the finite element model. The accuracy of the proposed model is verified using linear analysis via the comparison of the dynamic characteristics. For collapse risk assessment of OWT, the nonlinear effects considering the earthquake Incident Angle (IA) have been evaluated first. Then, the Incremental Dynamic Analysis (IDA) has been executed using a set of 20 near-fault records. Lastly, fragility curves are developed to evaluate the vulnerability of structures for different limit states. Attained results justify the accuracy of the proposed approach for the structural response against the ground motions and other environmental loads. It indicates that effects of static wind and wave loads along with the earthquake loads should be considered during the risk assessment of the OWT structure.

这项研究提供了使用分布式可塑性方法的海上风力发电机（OWT）结构的非线性行为的见解。应用纤维截面梁柱单元建立有限元模型。通过对动力学特性进行比较，使用线性分析验证了所提出模型的准确性。对于OWT的倒塌风险评估，首先评估了考虑地震入射角（IA）的非线性效应。然后，使用一组20条近故障记录执行了增量动态分析（IDA）。最后，建立脆弱性曲线以评估结构在不同极限状态下的脆弱性。获得的结果证明了所提出的方法对地面运动和其他环境载荷的结构响应的准确性。