Generation of 3D representative volume elements for heterogeneous materials: a review

Mechanical modelling of 3D woven composites considering realistic unit cell geometry

The increasing developments in wind turbine technology, coupled with an unpredictable operating environment, present significant challenges regarding erosion issues on the leading edge of the blade tips. This review examines the potential degradation posed by the different environmental variables, with specific emphasis on both rain droplet and hailstone impact on the blade leading edge. Drawing on both the insights from experimental results and recent field data from the literature, the mechanisms of leading edge erosion are discussed. Meteorological tools that may enable rain and hailstone erosion prediction are addressed, as well as potential experimental and numerical approaches that may provide insight into the nature of impact and erosion on the blade surface.

/pdf/on-erosion-issues-associated-with-the-leading-edge-of-wind-2itin3tko1.pdf

On erosion issues associated with the leading edge of wind turbine blades

Meso-scale FE analyses of textile composite reinforcement deformation based on X-ray computed tomography

3D composite reinforcement meso F.E. analyses based on X-ray computed tomography

https://research-information.bris.ac.uk/files/34815001/Green_Comp_Struct_2014_3D_woven_deformation_FE_pre_print.pdf

Numerical modelling of 3D woven preform deformations

A multi-scale approach to modelling is optimal for computationally intensive problems of a hierarchical nature such as 3D woven composites. In this paper an approach capable of modelling feature/component scale fabric deformations and defects is proposed. The proposed technique starts with a meso-scale model for predicting the as-woven geometry of a single unit cell using a high fidelity digital element method. The unit cell geometry is then converted into a macro-scale fabric model by geometric reduction then tessellation. On the macro-scale, two and three dimensional approaches to yarn geometry representation are proposed, with an accompanying yarn mechanical model. Each approach is evaluated based on solution accuracy and computational efficiency. The proposed approach is then verified against experimental results on the meso- and macro-scales. The applicability of this modelling technique to larger scale compaction problems is then investigated. The proposed algorithm was found to be accurate and computationally efficient.

/pdf/kinematic-modelling-of-3d-woven-fabric-deformation-for-3lhx9e8kzq.pdf

Kinematic modelling of 3D woven fabric deformation for structural scale features

Alternative structural layouts for wind turbine blades are investigated with the aim of improving their design, minimizing weight and reducing the cost of wind energy. New concepts were identified using topology optimization techniques on a 45 m wind turbine blade. Additionally, non-dimensional structural shape factors were developed for non-symmetric sections under biaxial bending to evaluate structural concepts in terms of ability to maximize stiffness and minimize stress. The topology optimization evolves a structure which transforms along the length of the blade, changing from a design with spar caps at the maximum thickness and a trailing edge mass, to a design with offset spar caps toward the tip. The shape factors indicate that the trailing edge reinforcement and the offset spar cap topology are both more efficient at maximizing stiffness and minimizing stress. In summary, an alternative structural layout for a wind turbine blade has been found and structural shape factors have been developed, which can quantitatively assess the structural efficiency under asymmetric bending.

/pdf/structural-efficiency-of-a-wind-turbine-blade-1vou2g2ulf.pdf

Steven D Green

Papers

Mechanical modelling of 3D woven composites considering realistic unit cell geometry

Numerical modelling of 3D woven preform deformations

Kinematic modelling of 3D woven fabric deformation for structural scale features

Structural efficiency of a wind turbine blade

On the structural topology of wind turbine blades