Bend testing determines a material’s flexural properties, which are critical for quality control and specifications purposes. Properties measured include flexural stress, flexural strength, flexural offset yield strength, flexural strain, strain at a given strain, Tangent Modulus of Elasticity, Secant Modulus, and Chord Modulus.
During a bend test, a test specimen rests on two supports and is loaded by means of one or multiple loading noses. The stress-strain or load-deflection curves obtained from a bending test provide useful information on a material in addition to equations that can be used to calculate its flexural property values. Some materials give a load deflection curve with a break point and no yield. Other materials exhibit both a yield and a break point which can be visualized on a yield deflection curve.