The innovative GZ B-20 bending test fixture enables all common bending tests on fibre-reinforced plastics to be carried out with just one test fixture. All support spans required for this can be flexibly adjusted with this test fixture. The principle of the bending test consists in the use of a two-part bending test fixture in which the specimen is clamped as a bending beam between two outer supports and loaded via an inner support (3-point bending) or two inner supports (4-point bending). For bending tests on fibre-reinforced plastics, the methods according to DIN EN ISO 14125, DIN EN ISO 178 and ASTM D790 are usually used. For this, a 3-point or 4-point load can be realised in the bending test.

By means of the various test methods for composites, the flexural strength and the flexural modulus are determined under a bending load of the test specimen at defined test conditions. The test is carried out at constant speed up to a specified deformation or until failure of the test specimen. As a result, the bending stress, the bending modulus and the elongation at failure are determined.