Tensile test on composites

Tensile and tensile shearing tests are performed in a variety of ways.

Industry brochure: Composites PDF 7 MB
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Tensile tests on single filaments

The diameter of the individual filament lies in the micrometer range. The filament is first secured to a small paper frame according to ISO 11566 and then aligned and fixed in the clamping mechanism of the testing machine. After cutting through the frame, the properties can be determined under tensile load.

Tensile tests on filament strands

Normally, the filament strands are coated in resin first and then cut into lengths. Cap strips made from cardboard or plastic are glued to the ends so that the tensile force can be applied evenly to the specimen. Tools such as the makroXtens and multiXtens extensometers are ideal for measuring elongation.

Tensile tests on unidirectional laminates

Unidirectional laminates are normally tested longitudinally for fiber strength and transversely for bond strength. The specimens are reinforced at the ends with cap strips to avoid jaw breaks. This test, which is described in ISO, ASTM, EN, AITM, BSS, DIN, SACMA and CRAG standards, places high demands on the quality of the extension measurement and on the alignment accuracy.

Tensile tests on multidirectional laminates

Depending on the size of the textile structure, multidirectional laminates are tested with large specimen widths of 25 mm or even 50 mm. According to ISO 527-4, the thickness of the specimen can equal 10 mm or less. Due to the large specimen cross-sections, very large tensile forces of over 300 kN can occur.

To measure strain, ZwickRoell uses strain gauges, mechanical extensometers (clip-on, makroXtens, multiXtens) or optical extensometers (videoXtens HP).

Notch tensile tests (open hole tensile)

This test characterizes the influence of a hole on the tensile strength of a laminate. The result is usually presented as a notch factor, which gives the ratio of damaged to undamaged specimen.

Tensile tests on bolted laminates (filled hole tensile)

This test uses the same specimen as the notch tensile test, and the hole is closed with a threaded connection.

Testing composites to ISO 527-4/-5 in a wide temperature range

Testing composites to ISO 527-4 and ISO 527-5 in a wide temperature range

2D DIC – test on fiber-reinforced composites

2D DIC: a powerful analysis tool

2D digital image correlation visualizes deformations and strain over the entire visible specimen surface. The non-contact videoXtens extensometer records image series during the test, compares image for image, and calculates the displacement in a pre-defined facet field, whereby each facet comprises a certain number of camera pixels. This data is used to create two-dimensional color strain maps, which allow you to analyze the specimen behavior at a glance.

If you are looking for the optimal solution for each of your requirements, please contact our industry experts.

We look forward to discussing your needs.

videoXtens

Extensometers

The non-contact ZwickRoell video extensometers are ready for nearly any test task. From determination of the Poisson’s ratio on fiber-reinforced composites in a temperature chamber, to automated break location identification on metals and high-extension elastomers, complete videoXtens systems offer optimal configuration options for special applications.

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laserXtens

Measuring completely without gauge marks, without making contact and with the highest level of accuracy—these characteristics are at the core of the laserXtens. The patented laserXtens is based on very high accuracy, measures with the highest level of precision and offers a wide variety of evaluation possibilities. All of this with very easy operation, and since no specimen marking is required a lot of time is saved.

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