Aeroelastic divergence and flutter: Critical comments on the regulations of EN 1991-1-4

The European wind-load standard EN 1991-1-4 (2010) contains regulations that deal with aeroelastic instabilities of structures. These are discussed and commented on in this article. Numerical calculations are used to corroborate the comments. It is shown that some of the regulations do evidently not provide generally applicable criteria to avoid aerolastic instabilities. On the basis of the statements made in this article, a modified text is proposed for the standard. A numerical example serves to explain the regulations regarding aeroelastic divergence.