Instron 4400 Series Operator's Manual page 245

Minimum Bend Radius.
Minimum radius to which a sheet or wire can be bent to
a specified angle without failure.
Modulus.
Alternate term for modulus of elasticity, often used in
connection with rubber.
Modulus in Bending.
Ratio of maximum fiber stress to maximum strain,
within elastic limit of stress-strain diagram obtained in
flexure test. Alternate term is flexural modulus of elastic-
ity.
Modulus of Elasticity.
Rate of change of strain as a function of stress. The
slope of the straight line portion of a stress-strain dia-
gram. Tangent modulus of elasticity is the slope of the
stress-strain diagram at any point. Secant modulus of
elasticity is stress divided by strain at any given value of
stress or strain. It also is called stress-strain ratio. Tan-
gent and secant modulus of elasticity are equal, up to the
proportional limit of a material.
s1 s1
Tangent modulus
of elasticity
= sl/a
Secant modulus
of elasticity
= s1/e1
e1
STRAIN
a
Glossary
e1
STRAIN
a
B-19