Fatigue evaluation of grouted connections under bending moment in offshore wind turbines based on ABAQUS scripting interface

Abstract

The fatigue behavior evaluation under bending moment is extremely important to the grouted connection in monopile offshore wind turbines. Based on the scripting interface of ABAQUS software, finite element model of the grouted connections was established automatically in accordance with the user defined parameters by Python language. Based on the experimental material test of grout material, the grout material was simulated by using three-dimensional concrete damaged plasticity (CDP) model in ABAQUS. Full model and half model were compared under fatigue limit state (FLS), and numerical results are presented in terms of hot spot stress in steel and third principle stress in grout material. It was found that half model could decrease calculation time significantly with more conservative evaluation result. Furthermore, parametric studies were conducted based on the half models about two different shear keys’ arrangements as well as the height and distance of shear keys. And it is found that there are slight differences for two models in calculated design life when the interface behavior between steel and grout material is modeled by Coulomb friction law.