Tensile strengthUTS

The stress at which a material begins to deform permanently rather than elastically. Loading beyond the yield point leaves residual deformation after unloading; many brittle materials, including cured thermoset laminates, fracture without showing a distinct yield.

The strain at which a specimen ruptures in a tensile test, expressed as a percentage of its original length. High values indicate a ductile or flexible material such as an elastomeric roofing membrane, while rigid laminates typically fail at low elongation.

A measure of a material's stiffness, defined as the ratio of stress to strain in the elastic region of loading. A higher modulus means less deflection under a given load; for plastics and composites it is typically measured in tension to ISO 527.

A mode of loading that stretches a material along its axis. Fibres such as carbon and glass are most efficient in tension, which is why laminates are orientated so that the fibres carry the principal tensile loads.