**4. Fluid–Structure Interaction—Structural Assessment**

The next step of the study covers the structural assessment of the blade and the entire wind turbine. Under inspection will be the taken stresses and deformations. The evaluation of stresses appearing in the material allows assessing the safety of the structure—whether the structure will not start to crack or creep. Deformations, meaning tip deflections and cross-sectional twist, provide information about potential changes of the airflow around the blade.

It is important to underline that the FSI simulations receive relatively little attention for SWTs of 1-kW power range since their blades are usually less prone to rupture than those of megawatt-size machines (due to, for instance, more uniform rotor disc loading). The current study shows that the FSI successful application due to two chief aspects: to ensure that the applied, unorthodox material can withstand severe loads, and to try to estimate the influence of blade deformation due to the aerodynamic loads and check if this is a major concern for this size of machines.
