4D-Printing Creates Lighter Turbine Blades

A new 4D-printing technique creates lightweight composite wind turbine blades that spin faster, weigh less, and could reduce manufacturing costs.

Researchers at Concordia University have developed a manufacturing technique based on 4D printing of composites that could make small wind turbines lighter, cheaper and easier to fabricate. The technology uses curved blades for vertical-axis wind turbines that are fabricated from flat panels made of carbon-fibre composites. 

This novel fabrication process resulted in blades with shapes resembling those of commercially available aluminium blades, although they weighed 80 per cent less. Laboratory tests showed that vertical-axis wind turbines with such blades rotate faster than the turbines that were equipped with aluminum blades. The researchers said that the proposed technique could lower manufacturing costs and increase the applicability of lightweight composites in renewable energy and other engineering applications.

Vertical-axis wind turbines are currently widely used in buildings and urban areas, but the manufacture of their curved blades requires special procedures and expensive moulds. This makes the fabrication process lengthy and adds additional weight to the turbines. To solve the problem, the scientists developed a one-of-a-kind “inverse” design procedure.

Instead of starting with a specific layup, which refers to the arrangement and orientation of the carbon-fibre layers, and observing the resulting shape, the scientists first designed the blade geometry and, then, figured out how the layers were supposed to be oriented to create it.

Flat carbon or epoxy laminates deform into curved shapes during cooling after being cured. The curvature is achieved through carefully engineered differences in material properties across the layers.