Each claim states how it is known and cites its evidence.
EstablishedReinforcement carries load; matrix positions, protects and loads the reinforcement and limits service temperature.
In a structural composite the reinforcement carries most of the load and gives the material its strength and stiffness, while the matrix holds the reinforcement in position and orientation, transfers load into it, protects it from abrasion and the environment, and sets the maximum service temperature of the composite.
Evidence support: Supported by the cited evidence · 3 sources, multiple sources, independence unknown
Evidence: U.S. Department of Energy 2015 · Primary authority; U.S. Department of Transportation, Federal Aviation Administration, Flight Standards Service 2023 · Primary authority; L. 2016 · Peer-reviewed
EstablishedTwo or more constituents that remain distinct in the product and act together, usually a reinforcement in a matrix.
A composite combines two or more materials that keep their own identity in the product rather than dissolving or merging into one another; the constituents act together, can normally be told apart where they meet, and can be chosen so the combination outperforms each of them. Structural composites usually pair a reinforcement with a matrix.
- definition basis: Definitions given by the U.S. Department of Energy composite technology assessment and the FAA airframe handbook; the two agree and neither defines composites more narrowly than the other.
Evidence support: Supported by the cited evidence · 2 sources, multiple sources, independence unknown
Evidence: U.S. Department of Energy 2015 · Primary authority; U.S. Department of Transportation, Federal Aviation Administration, Flight Standards Service 2023 · Primary authority
EstablishedThe fibre–matrix interface transfers load; its bond strength must be neither too weak nor too strong.
Load passes between matrix and reinforcement across the interface between them, so the strength of the fibre–matrix bond governs how well the reinforcement works: too weak a bond wastes the reinforcement, while in brittle systems a bond that is too strong lets cracks run straight through and lowers toughness. In fibre-toughened ceramics the interfacial bonding is a primary control on fracture toughness.
- precision note: The two sources speak from different composite families — natural fibre polymer composites and ceramic-matrix composites — and agree on the mechanism; neither gives a bond strength that is right for composites in general, and none is asserted here.
Evidence support: Supported by the cited evidence · 2 sources, multiple sources, independence unknown
Evidence: L. 2016 · Peer-reviewed; Jon 2020 · Peer-reviewed
EstablishedContinuous or discontinuous reinforcement; laminate properties set by ply orientation and stacking sequence.
Reinforcement may be continuous or discontinuous, long or short; in a laminate the stiffness, strength and dimensional stability depend on the stacking sequence of the plies, a unidirectional ply being strong and stiff only along its fibres, a bidirectional fabric in two directions, and a quasi-isotropic lay-up of plies at 0°, ±45° and 90° approximating uniform properties.
Evidence support: Supported by the cited evidence · 2 sources, multiple sources, independence unknown
Evidence: U.S. Department of Energy 2015 · Primary authority; U.S. Department of Transportation, Federal Aviation Administration, Flight Standards Service 2023 · Primary authority