Various fiber composites are used in technical applications

  • Glass fiber reinforced plastics (GFRP)
  • Carbon fiber reinforced plastics (CFRP)
  • Aramid fiber reinforced plastics (AFRP)
  • Natural fiber reinforced plastics (NFRP)


The fiber composites consist of the fiber in the form of a filament or staple fiber, e.g. as roving, and a matrix that provides the necessary bond strength.

The characteristics profile, in addition to the choice of fiber and matrix material, is largely determined by the orientation of the fibers in the textile fabric. For the requirements of testing technology, a distinction is usually made between unidirectional and multidirectional laminates.

As a rule, the materials test represents individual load scenarios on standardized specimens. Due to the strong directional dependency of the properties, the various load types are performed using different specimens, e.g. longitudinal and transverse to the main fiber direction.

In addition to the international standard (ISO), these tests are described in various national or regional standards (ASTM, EN, DIN), as well as in internal company regulations (Airbus AITM, Boeing BSS). The result of this is an environment of more than 150 standards, which describe around 20 generic testing methods.

The testing of components, structural cutouts and entire structures is generally based on the loads that occur in subsequent operation. Attention is also paid to strengths, energy-absorption (crash), material fatigue and service life estimates.

Due to the directional and shearing sensitivity of the fiber composites, test forces must be precisely applied in the intended direction. The axiality error is described as ‘alignment’ and is subject to narrow tolerances. To measure the alignment, Zwick uses special measuring devices which orient themselves to the shape and dimensions of the specimen. The tensile axes of the testing machine are oriented using mechanical alignment fixtures