Effect of structural nonlinearity on probabilistic risk assessment of offshore wind turbine including inelastic soil medium

摘要

This research intends to evaluate the influence of structural nonlinearity on the seismic risk of an offshore wind turbine with respect to linear analysis. The structural nonlinearity is presented into the structure, as materially nonlinear, by calibrating plastic hinge at the end of the elastic beam-element of the structure. To guarantee ideal circumstance for seismic analysis, this study includes inelastic soil stratum by using an equivalent linear approach. Monte Carlo simulation is performed by means of seismic vulnerability of the structural system. The research presents a study of a large amount of simulation over the nonlinear and linear structures considering the random character of basic variables of soil under selective earthquakes. The earthquakes having different source-to-site (STS) distances ranging from 7 to 145km have consistency with the soil parameters. This rigorous implementation is done to accomplish site-specific dynamic analysis. Illustrative results obtained from nonlinear and linear dynamic analysis are compared. The overall finding shows that the nonlinear structure produces highest estimated uncertainty compared to the linear structure. Another termination can be addressed that the earthquake with less STS distance (7.29km) causes the highest level of destruction to the structure.