Posts Tagged ‘sandwich structures’
There is a new market research report out from QY Research Group on the “2010 China Wind Turbine Nacelle Cover and Nose Cone Industry”. The report, which costs $2,500 USD will go into detail on the manufacturing of composite nacelle covers, and will likely talk about the use of sandwich structures to make this product lightweight, yet strong.
The strong, stiff, and lightweight nature of sandwich panels make them an ideal fit for numerous applications. In yet another example, Business Wire reports that the new Ferrari JBL speakers utilize a sandwich construction:
“The diaphragms in the specially developed sound transducers feature a three-layer sandwich structure with pure aluminum backing to minimize distortion across a wide range of frequencies for particularly authentic reproduction of voices and instruments.”
Here is an interesting video demonstrating the vacuum assisted resin transfer molding process of a seven layer composite sandwich panel with a unique thin honeycomb core.
Above is a short video about how a composite sailboard is made, quite interesting… Notice that this sporting good is actually a complex composite sandwich structure made with various layers of material, and molded with precision.
A common composite sandwich structure used every day by people in coastal cities across the world are surfboards. Generally, a shaped polyurethane foam core with a wooden stringer, is laminated by multiple layers of 12oz or 14oz 0/90 e-glass fabric, using a vinyl ester resin.
In recent years, more advanced composites are being integrated into surfboards, below is a video on how lightweight windsurfing boards (aka composite sandwich structures) are made using aerospace grade materials.
In the building of large composite structures, such as the new the new aircraft by Airbus and Boeing, the use of computer modeling is playing an increasingly important role. The same is true in the design of composite sandwich structures used where weight, specifications, and cost are important.
By using what is called, “Finite Element Analysis”, or FEA, engineers can model a composite sandwich structure, and closely predict loads and failure points prior to actually constructing a panel. The engineer can vary skin and core material in the design, and vary lay-ups and ply schedules of the composite face sheets.
Doing this often elements the “guess and check” method of using composites for a product. Optimization allows the composite sandwich structure to meet all required levels of compression and shear stregth, while eleminiting any excess materials. This helps reduce weight, which is often the reason in selecting composites in the first place. Additionally, when weight is reduced and less material is used, costs go down, and this is important for everyone.
Here is a link to a recent NASA Tech Brief.
Popular FEA software used in composites include:
This past week in Palm Springs, CA the Fall Symposium for the American Wind Energy Association (AWEA) took place. With the troubling times in financial markets, and conventional energy costs low, the renewable energy sector is due for some slowing. Regardless of the current issues, the long term future of renewable energy, and wind in particular is still extremely bright.
At the conference, a major theme was the need to continue the push of technology advancements in wind turbine systems. The use of lightweight composite sandwich structures in wind blades is already prevalent, however, advancements are still needed. It is crucial that wind blades of the future use less material, become lighter, and the manufacturing becomes more reliable and automated.
Sandwich structures and their lightweight benefits will help lead this charge. New cost effective core materials are required; these need to be lightweight and exhibit high sheer properties, but cost will be the underlying issue. E-glass is the current predominant fiber reinforcement, however hybrid fabrics using limited amounts of carbon fiber could help lower weights without adding too much additional costs.
New resin systems and production techniques will help streamline manufacturing and lower defects and voids.
Wind blade manufacturers need to turn to composite experts and begin the adaptation of advanced composites, fiber, and sandwich techniques into wind blade manufacturing.
New developments in the continuous monitoring of composite sandwich structure health and environment through the embedding of connected fiber optic sensors.
Read the Article at SPIE