Table of Contents
Advertisement
Glossary
M10-94400-1
Relaxation.
Rate of reduction of stress in a material due to creep.
An alternate term is stress relaxation.
Residual Elongation.
Measure of ductility of plastics. It is the elongation of a
plastic specimen measured 1 minute after rupture in a
tension test.
Rupture Resistance.
Indication of ability of rubber to withstand tensile load-
ing. It is the load required to rupture a rubber specimen
under conditions set out in ASTM D-530.
Rupture Strength.
Nominal stress developed in a material at rupture. It is
not necessarily equal to ultimate strength. And, since
necking is not taken into account in determining rupture
strength, it seldom indicates true stress at rupture.
S-N Diagram.
Plot of stress (S) against the number of cycles (N) re-
quired to cause failure of similar specimens in a fatigue
test. Data for each curve on an S-N diagram are obtained
by determining fatigue life of a number of specimens
subjected to various amounts of fluctuating stress. The
stress axis can represent stress amplitude, maximum
stress or minimum stress. A log scale is almost always
used for the N scale and sometimes for the S scale.
B-26
Advertisement
Table of Contents
