Optimization of Shear Bonds of the Grouted Joints of Offshore Wind Turbine Tower Based on Plastic Damage Model

In recent years, offshore wind power has been developing rapidly, and single piles are among the commonly used foundations for wind turbines. Presently, experimental studies of the grouted connections of pile foundations are limited to the study of scaler models. Numerical simulations are more suitable for the mechanical analysis of the full-size structure instead of experimental ones. In numerical simulations, the linear elasticity model is widely adopted, but the plastic damage is studied scarcely. So, shear bond parameter research concerning grouted joints needs to be supplemented. In this paper, a bilinear random-motion reinforcement model based on the classical metal plasticity theory is adopted for steel, and the model for the grouting material is based on the Sidiroff energy equivalence principle. The plastic damage model for the grouted connecting section is established; the stresses and deformation distribution of the steel pipes and grout in the connecting section are analyzed using the changed shear bond parameters. The results show that the rectangular and triangular shear bonds are more reasonable than the semicircular shear bond transfer. Increasing the height of the shear bond may reduce the maximum stress and the maximum vertical displacement of the grout, and the shear bond width change has less influence on the joint bond stress and displacement.