Bend/Flex Testing

The three-point bend testing provides values for the modulus of elasticity in bending and the flexural stress–strain properties of the material being tested. One advantage of three-point flexural testing over other methods is the ease of the specimen preparation. Very little preparation is usually required. A deflection coil may also be implemented and placed under the sample being tested to give a more accurate measurement of displacement versus just measuring the displacement of the crosshead travel. Four-point bend testing is similar, the major difference is that the addition of a fourth loading point brings a much larger portion of the beam to the maximum stress. This is most noticeable when studying brittle materials.