Large composite structures, when manufactured with high-performing thermoplastic materials, can offer significant weight savings and environmental resistances when compared to alternative materials such as metals. Building on this, thermoplastic composites can be used to create structures reinforced with composite stiffeners. This heightens the advantages of composites allowing for even lighter designs while also broadening the range of possible geometries. A great example is the composite tail boom (pictured above) detailed in Composites World.
The Thermoplastic Advantage
Compared with traditional metal materials, neat (unreinforced) plastics, and even thermoset composites, fiber-reinforced thermoplastic composites:
- Have dramatically superior strength-to-weight capabilities
- Offer lighter, less brittle, tougher parts
- Possess greater fatigue properties
- Provide greater resistance to corrosive chemicals, water absorption and heat
- Utilize Out-of-Autoclave (OoA) processing that drastically reduces cycle times and energy consumption
As an additive manufacturing process, AFP of thermoplastic composites trims significant time and expense during manufacturing. Thermoplastics are recyclable and repairable, which cuts down on waste, and their ability to bond to differing materials enables the creation of hybrid structures.
The inherent benefits of thermoplastics lend themselves well to composite stiffeners. They are ideal for a wide variety of shapes and sizes as AFP can be used to create complex structures beyond just flat surfaces or tubes. Specifically, thermoplastic composites can be molded into an assortment of stiffener shapes including I, C, and hat stiffeners (see images).
- A thermoplastic composite stiffener has 20x the specific strength of a 6061-T6 grade aluminum stiffener.
- Composite beams are as much as 30% lighter than other common materials.
- The stiffness of a composite I-beam is comparable to an aluminum I-beam once weight is factored in.
- Thermoplastic stiffeners can be cobonded with larger thermoplastic skins resulting in reinforced structures without the need for fasteners.
- There are no decreases in strength due to the bonds as bond line fracture is not the primary mode of failure for cobonded structures.
For more information and detailed descriptions of these processes, visit our Resources page for technical papers and presentations, or contact us today using the button below!