The flexural modulus (E_f) is a special case for the tensile modulus E, describing the resistance the material offers to bending. The resistance to bending depends on the distance between the two supports (correlated to length of the sample) and the point of application of the force at the center, but also on the thickness of the sample and its width. The standard equation must therefore include all variables, and L is the distance between the supports, F is the force, w is the width of the sample, h is its thickness, d is the deflection.

The flexural experimental setup is based on the use of only one of the four actuators of the biaxial tester, applying orthogonal force at the center of the sample while it is resting on a support allowing it to bend from two fixed points in a “three-point bending” procedure.

The steel plate moves perpendicular to the center of the sample at the speed of 0.5 mm/min, reaching it with a rounded contact blade parallel to its surface. The experimental setup meets the ASTM D 790 – 07 standard.

The following flexural test plot shows a wide linear response area.