Three-dimensional stress investigation for wind turbine

Abstract

With the depletion of natural resources, the world is getting more reliant on alternatives energy resources like solar and wind energy. The focus of this project is the wind turbine, which converts wind energy into electricity. In order for wind turbine to be cost effective compared to tradition energy sources, it needs to maintain its reliability with lesser maintenance and failures. This project looks at the structural failure of the Enercon’s E-126 wind turbine tower simulated with semi-elliptical surface cracks of different geometry and location under static wind loading. In order to evaluate this situation, the fracture criterion of this tower was analyzed based on past researches. Eventually, the 3D crack models created were successful meshed and Finite Element Analysis (FEA) was conducted using the ABAQUS software to determine the J-integral value along the surface crack. It was found that the J value was dominated by fracture mode I while mode II and III had insignificant contribution to the J value. Next, it was also observed that an increasing c/a ratio for the semi-elliptical crack would result in higher Ki value at the midpoint of the crack tip. When the c/a ratio was set more than 1.5, the Ki at the midpoint of the crack tends to surpass the Ki value at the both ends of the crack tip.