Sino-Danish cooperation on wind turbines

The high reliability of wind turbine blades is especially important for large and extra large wind turbines. It can be ensured by the development of strong and highly damage resistant advanced materials. The Materials Research Division at Risø DTU has received a grant from the Danish Council for Strategic Research to develop the scientific basis and computational tools for the microstructural optimization of materials for wind blades.

In a newly approved project, the scientific basis for the development of advanced, strong composites for wind blades, by optimizing their structures at microlevel, is to be created. This will be achieved by carrying out a comprehensive materials testing programme, and through the development of a “virtual laboratory” for the computational testing of different materials for wind blade applications. Different ways of modification and optimization of wind blade materials microstructures (including nanoengineered composites and hierarchical materials) will be explored in numerical experiments.

Exact methods to predict the lifetime and strength of different blade materials under complex cyclic and environmental loading, as well as recommendations towards the improvement of performances of composites for wind turbine blades will be developed.

The new project includes the collaboration with the China University of Mining and Technology, Beijing. Risø DTU has a good experience of collaboration with the China University of Mining and Technology, Beijing. Several students from CUMTB have been visiting Risø during the last years supported by scholarships from Chinese Academy of Sciences. One of the previous joint projects was the project “3D virtual testing of composites for wind energy applications: Computational mesomechanics approach” supported by the Danish Agency for Science, Technology and Innovation, and Danida.

As a result of this collaboration, a number of papers have been published in leading international journals. The project manager (of the entire project, and of the Danish part) is Leon Mishnaevsky, senior scientist in the Materials Research Division at Risø National Laboratory for Sustainable Energy at the Technical University of Denmark (DTU). The project will run for 3 years and has a budget of DKK 5, 5 million.

High reliability of large wind turbines via computational micromechanics based enhancement of materials performances

The goal of this project is to create a scientific basis for the development of advanced, strong materials for wind blades by optimizing their structures at microlevel.

The future of wind power is related with the design of very large wind turbines (8-10MW) standing in wind farm plants of several hundred MW, both on- and offshore. In this case, the potential costs of repair and replacement of damaged wind turbines will be huge. Thus, the problem of ensuring high reliability of wind turbines becomes especially important for large and extra large turbines. The required reliability of wind turbines can be ensured by development and use of strong and highly damage resistant advanced materials. The goal of this project is to create a scientific basis for the development of advanced, strong materials for wind blades by optimizing their structures at microlevel. This goal is achieved by carrying out comprehensive materials testing programme (incl. in-situ under electron microscopy) (which allows to clarify the complex damage and degradation mechanisms in wind blade materials), by development of a “virtual laboratory” for the computational testing of different materials for wind blade applications and exploring different ways of modification and optimization of wind blade materials microstructures (including nanoengineered composites and hierarchical materials) in numerical experiments. Exact methods to predict the lifetime and strength of different blade materials under complex cyclic and environmental loading, as well as recommendations toward the improvement of performances of composites for the wind turbine blades are developed.

The objective of this project is to create a scientific basis for the development of advanced, strong materials for blades of large and extra-large wind turbines by optimizing their structures at microlevel. The intermediate goals include:

* Development of “virtual laboratory” for the computational testing, comparison and optimization of different microstructures of wind blade materials,
* Predictive models of lifetime and reliability of wind blade materials, taking into account the microscale mechanisms of strength and real microstructures of materials,
* Determination of microscale physical mechanisms and microstructural parameters governing the damage resistance and strength of wind blade materials. In order to do it, a comprehensive program of the experimental and theoretical studies is planned
* Analysis of the environmental effects on the strength and lifetime of the wind blades,
* Exploring future directions of wind blade materials development: Nanoengineered matrix and hybrid composites, their usability and efficiency as compared with usual composites
* Development of computational programs for the optimal choice of wind blade materials corresponding to given service requirements

The wind power project is funded by the Danish Council for Strategic Research. The budget is 4.99 Mio Kroner (about 670 K€) and lasts frm 2011 til 2014. The wind energy project includes the collaboration with the China University of Mining and Technology, Beijing (Professor Hongwei Zhou).

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