Offshore Wind Turbine Foundation Flange Study

Abstract

The purpose of this research is to study the conditions of bolted flange connections for offshore wind turbines. In this particular study, M72 bolts preloaded up to three hundred tonnes will be analysed. The research will be based on full-scale and fully detailed FEM simulations, in order to obtain the most reliable results possible, of a one bolt segment of the flange. There will be two different lines of work involved in the research. The first of them will be studying the effect friction has on the distribution of tensions along the thread, and its effect on overall loading of the bolt. These simulations will focus only on the instant of application of the load. Therefore, the following section of the research will try to model short-term relaxation as a form of room temperature creep. The variation of bolt tension through time will be studied considering different creep properties, being these conditioned by temperature and material properties