Effect of Fiber Orientation on Properties
The way the fibers are oriented in a carbon fiber or fiberglass layup affects the properties of its carbon fiber or fiberglass product, and these properties must be considered during design and production.
Below we explain how each common fiber orientation affects performance:
1. 0° direction
If a part is only loaded in one direction, it is best to have all fibers oriented in the same direction. Pultruded rods and tubes are examples of parts that contain only 0° fibers. Since most parts are not loaded in only one direction, additional angles need to be added to maximize strength. Adding a 90° layer helps the tube better retain its shape so it doesn’t bend prematurely.
2. 90° direction
As mentioned earlier, 90° plies are often added to tubes to make them more resistant to buckling and crushing. High concentrations of 90° or “ring” layers can also be found in pressure vessels. Since the force tries to expand the tube in the pressure vessel, the 90° layer is the most resistant. When a 90° layer is used in combination with a 0° layer in the board, it is called bidirectional. Using a woven cloth is an easy way to quickly build fiber parts in both 0° and 90° orientations.
3. ±45° direction
The carbon fiber material 45° ply has different uses depending on the application. It is extremely common for a +45° to be adjacent to a -45° ply, this is to keep the laminate “balanced” and not twisted with force when loaded. When a 45° ply is used in a slab that already contains an equal mixture of 0° and 90° plies, the slab becomes quasi-isotropic. Bidirectional slabs have equal properties in both directions, while quasi-isotropic slabs have quasi-equal properties in any direction. In the tube, the 45° plies do the work of adding torsional strength and stiffness. That’s because when the tube is twisted, the force acting on the laminate is forty-five degrees. Some laminates will use angles other than 45° as a compromise between bend, crush and torsion performance.
Choose the correct fiber direction according to your needs
If you need a tube that will perform in all conditions, bi-directional layups are ideal; if you need a tube with good torsion performance, choose a product with more 45° layers; if you need to increase thickness quickly, braided material Might be a good choice.
