5 - Composites

Flashcards covering key vocabulary and definitions related to materials engineering for aerospace composites.

Composite

A combination of two or more individual materials designed to obtain a more desirable combination of properties.

CFRP

Carbon Fiber-Reinforced Polymer, a composite material comprising carbon fibers embedded in a polymer matrix.

GFRP

Glass Fiber Reinforced Polymer, a composite made of glass fibers within a polymer matrix.

Thermoplastic

Polymers that can be melted and shaped during fabrication.

Thermoset

Polymers that cure and set during manufacturing and cannot be remelted.

Elastomer

Polymers that are crosslinked chain molecules, such as rubbers and silicones.

Molecular Weight

The weight of a molecule, which influences the melting or softening temperatures of polymers.

Crystallinity

Degree of structural order in a polymer, impacting its strength and properties.

Crosslinking

The process of chemically joining two or more polymer chains together, enhancing rigidity.

Amorphous Polymers

Polymers with a disordered molecular structure that are rigid and glassy at low temperatures.

Linear Polymers

Polymers characterized by a straight chain of repeating units.

Branched Polymers

Polymers that have side chains branching from the main chain.

Network Polymers

Polymers with a three-dimensional network structure providing enhanced strength.

Young's Modulus

A measure of the stiffness of a material, defined as the ratio of stress to strain.

Tensile Strength

The maximum amount of tensile (pulling) stress a material can withstand.

Fiber Reinforcement

Adding fibers to a composite material to improve its mechanical properties.

Rule of Mixtures

A formula used to predict the properties of composite materials based on the properties of the individual components.

Stress-Strain Curve

Graphical representation of a material's response to applied stress, indicating elastic and plastic behavior.

Plastic Deformation

Permanent change in shape of a material under stress beyond its elastic limit.

Necking

The localized reduction in cross-sectional area of a material when subjected to tensile stress.

Fracture Toughness

The ability of a material containing a crack to resist fracture.

Creep Resistance

The ability of a material to withstand deformation under constant stress over time.

Fatigue Resistance

The ability of a material to withstand cyclic loading without failure.

Moisture Absorption

The tendency of polymers to absorb water, impacting their performance.

Specific Modulus

The ratio of elastic modulus to density, indicating material stiffness per unit weight.

Specific Strength

The ratio of tensile strength to density, indicating material strength per unit weight.

Vibration Absorbing Material

Materials such as rubber that can absorb vibrations to reduce noise and enhance comfort.

Shear Strength

The ability of a material to resist shear forces.

Chemical Structure

The arrangement of atoms within a molecule which determines the behavior of the material.

Fiber Orientation

The direction of fibers in a composite which affects its mechanical properties.

Continuous Fibers

Fibers that extend throughout the entire length of the composite for improved strength.

Discontinuous Fibers

Short fibers within a composite that provide strength but less effective load transfer.

Hybrid Composites

Composites made from two or more types of fibers within a single matrix.

Matrix Phase

The continuous phase in a composite that surrounds and supports the dispersed phase.

Dispersed Phase

The reinforcement in a composite material that provides strength and stiffness.

Aluminum Matrix Composites (MMCs)

Composites composed of aluminum as the matrix material to enhance properties.

Ceramic Matrix Composites (CMCs)

Composites that use ceramic materials as the matrix to improve toughness.

High-Strength Fibers

Fibers like carbon or aramid that enhance the strength of composites.

Polymer Matrix Composites (PMCs)

Composites that use a polymer as the matrix material.

Spherulites

Spherical aggregates of polymer crystallites that affect the properties of crystallizable polymers.

Thermal Conductivity

The ability of a material to conduct heat.

Impact Strength

The ability of a material to withstand a suddenly applied load without failing.

Fiber Length

The length of the reinforcing fibers which affects the mechanical properties of the composite.

Interfacial Bond Strength

The strength of the bond between the fiber and the matrix in a composite.

Pultrusion

A manufacturing process used to create composite materials with a constant cross-section.

Laminates

Composite materials made by stacking layers that provide improved mechanical properties.

Quasi-Isotropic Composites

Composites designed to exhibit nearly isotropic properties over a range of directions.

Hybrid Structures

Structures combining different materials to optimize properties for specific applications.

Film-Insert Molding

A technique for making composite structures by molding over a film.

Thermally Stable Materials

Materials that maintain structural integrity at elevated temperatures.

Ultrahigh Molecular Weight Polyethylene (UHMWPE)

A type of polyethylene with extremely long chains, providing enhanced strength and resistance to impact.

Biocomposites

Composites made from biodegradable materials to reduce environmental impact.

Natural Fibers

Fibers derived from plants or animals used for reinforcement in composites.

Fiber-Matrix Compatibility

The degree to which the fiber and matrix materials adhere and function together in a composite.

Recycling of Composites

The process of recovering and repurposing composite materials after their end of life.

Void Content

Spaces within a composite that may affect its performance and mechanical properties.

Strength-to-Weight Ratio

A measure of a material's strength relative to its weight, crucial for aerospace applications.

Surface Treatment

Processes applied to fibers before composite manufacturing to improve adhesion with the matrix.