Collapse analysis of wind turbine tower under the coupled effects of wind and near-field earthquake

摘要

In this paper, the pattern of wind turbine tower collapse as a result of the coupled effects of wind and an intense, near-field earthquake is investigated. The constitutive relation of the tower cylinder steel is simulated via a nonlinear kinematic hardening model, and the specific value of each parameter in the constitutive model is provided. A precise model of the tower structure coupled with the blade is created using a nonlinear, finite element method. This method is compared with the results from a static pushover test of a small cylindrical tower to validate the finite element modeling method in this research. Two earthquake wave sets are selected as inputs. One contains 20 near-field velocity pulse-like ground motion waves with various pulse periods; the other contains 20 ordinary far-field ground motion waves. A wind turbine tower with a hub height of 60 m is selected as an example for analysis. The dynamic response of this tower as a result of the coupled effects of the two ground motion wave sets and a transient wind load is calculated using nonlinear time-history analysis. The calculation results shows that the average horizontal displacement of the tower top as a result of the near-field velocity pulse-like ground motion is 33% larger than the case with far-field ground motion. Finally, the seismic collapse vulnerability curve of this wind turbine tower is calculated. The seismic collapse capacity of the tower is evaluated, and the seismic collapse pattern of the tower is analyzed.