HyperSizer for Composite Wind Blade Design

The multitude of possibilities that could be explored to save weight in a blade include varying the overall geometric shape, cross section thickness, and basic architectural layout.  Sizing of individual members include the thickness of the spar web, its panel types as being either a foam sandwich or solid laminate, details of the spar cap, and of course, the actual lay-up of the individual composite fabric plies.

The highly coupled response of all of these variables and their factorial combinations reach millions and require an automated process or software tool for rapidly performing trade studies to find the lightest weight and best performance composite wind blade.  In addition to  considering all of these combinations of variables, many different failure analyses need to be performed including instability failures such as overall buckling, local buckling of the spar web or surface skin, crippling of the cross section, and of course, the composite material strength analysis.

HyperSizer allows engineers to rapidly analyze over 100 different, non-FEA based failure modes for all load cases:

-Perform flat and cylindrical buckling, local buckling, post-buckling, and crippling for panel and beams

-Carry out analyses at both the ply and laminate levels for composite materials. At the ply level perform standard quadratic failure predictions such as Tsai-Wu

-At the laminate level perform Angle-Minus-Load (AML) or the Boeing 787 polynomial coefficient methods

-For both approaches, include CAI and BVID damage tolerance and OHC/OHT open-hole allowables that include

customer specific correction factors for process dependent fabrication

-In addition to classical lamination theory (CLT) in-plane stresses and strains, compute out-of-plane Z axis interlaminar shear and peel stresses for multi-axially loaded adhesively bonded joints and bolt/fastener bearing

-On a more advanced R&D level, perform micromechanic analysis on the individual fiber and matrix constituents and compute crack propagation for safe-life or fail-safe designs with fracture mechanics or with a continuum damage approach

-Results of the detailed analyses control the optimization process, are shown graphically on the FEM, and are reported along with sample calculations in the margin of-safety stress report

In addition to structural strength and buckling integrity, the overall blade stiffness needs to be optimized to maintain its intended aerodynamic shape.  Wing tip detection and twist limits can be set along with all strength and stability criteria, while performing parametric  trade studies of blade cross section geometries simultaneously with composite laminate layups to reduce both weight and tip deflections.

For more details...

  HyperSizer Wind Blade Design brochure

  Windpower Engineering Cover Story - Building the Better Blade with HyperSizer

Windpower Engineering article - 20% lighter wind blades with HyperSizer