A reduction of the retardation time as well as the parameter n (slope of the secondary creep
phase) also confirms these results.
All the samples in this study undergo a primary creep stage and secondary creep
stage, whereas sample no.
Al 2024 displayed secondary creep
after 200 h and 400 h for T6 and underaged conditions, respectively, while the experimental alloy with low content of Ag did not show a secondary creep
behavior for both aging conditions.
Currently, this model more fully describes the properties of weak soil as stress dependent stiffness and compression based secondary creep
. It should be noted that the SSC model takes into account both physical and geometric nonlinearity of soil deformation process.
As is generally the case for creep behavior, the creep curve can be divided into three main regions; the primary creep region where the strain rate decreases with the number of load cycles applied; the secondary creep
region where the strain rate is almost constant, otherwise known as the steady state strain rate; and the tertiary creep region where the strain rate increases rapidly up to failure.
The creep deflection reached 14.1 mm or the relative creep became 1.43 after 3 months, and then approached leveling off, i.e., the secondary creep
Although the differences between the secondary creep
rates of SnAg and SnAgCu alloys are marginal, when tested under constant stress and temperature the secondary creep
rate of SnAgCu or SnAg can exceed that of SnPb at stresses above a shear stress of 20 MPa.
may be physical or chemical in origin.
The secondary creep
is characterized by a steady state-like deformation under the constant load.
The plot consists of various stages of creep viz., primary creep because of relatively high strain rate and the secondary creep
with a subsequent attainment of steady state behavior.
The "CoCrC=Ta" alloy knew first a very short primary creep, then a not really long secondary creep
(constant rate of central point displacement), and finally a rapid tertiary creep leading to the contact of the central bottom face of the sample with the alumina support (about 1.4 mm of total displacement, after 25 hours of test).
This is followed by a region where the strain rate remains constant, [[??].sub.pl] (secondary creep
), and eventually the terminal region is entered (tertiary creep), where the strain rate gradually increases until strain localization is initiated and failure occurs: creep rupture.