Testing acc. to ISO 527-5: Plastics – Determination of tensile properties – Part 5: Test conditions for unidirectional fibre-reinforced plastic composites
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Our test laboratory performs tensile testing according to DIN EN ISO 527-5 to determine the tensile properties of unidirectional fibre-reinforced plastic composites. The standard is based on the general principles of DIN EN ISO 527-1 and specifies the particular test conditions for materials with aligned fibre reinforcement. Properties determined include tensile strength, tensile modulus and tensile strain as well as, where appropriate, Poisson's ratio.
The method is suitable for thermoplastic and thermosetting polymer-matrix composites reinforced with unidirectional fibres, rovings, fabrics or tapes, including prepregs. Typical reinforcement fibres include carbon, glass and aramid fibres. The method therefore complements FILK's testing capabilities for Functional Coatings and Composites.
Testing according to DIN EN ISO 527-5
Two different specimen types are used depending on the loading direction. Type A is used for testing parallel to the fibre direction, while Type B is used for testing transverse to the fibres. The specimens are clamped in a tensile testing machine and loaded at a defined test speed until fracture or until the specified test limit is reached.
Force and deformation are recorded throughout the test and used to determine the stress-strain relationship. Due to the pronounced directional dependence of unidirectional composites, accurate specimen alignment and controlled load introduction are particularly important.
Applications of the test
The test enables the mechanical properties parallel and transverse to the fibre orientation to be characterized separately. This allows the contribution of the fibres to longitudinal strength and the behaviour of the matrix and fibre-matrix interface in the transverse direction to be evaluated.
The results are particularly relevant to material comparison, materials development, laminate design, process optimization and quality control of fibre-reinforced composites.
Related tests
Within the DIN EN ISO 527 series, DIN EN ISO 527-1 specifies the general principles of tensile testing. DIN EN ISO 527-2 applies to moulding and extrusion plastics, while DIN EN ISO 527-3 covers films and thin sheets. Isotropic and orthotropic fibre-reinforced plastic composites are tested according to DIN EN ISO 527-4.
The flexural properties of fibre-reinforced plastic composites can additionally be determined according to DIN EN ISO 14125.
