Civil Engineering Reference
In-Depth Information
sections. On the other hand, destructivemethods involvemachining/cutting
of the cross section to release internal stresses and measure resulting change of
strains. Destructive methods are based on the destruction of the state of equi-
librium of the residual stresses in the cross section. In this way, the residual
stresses can be measured by relaxing these stresses. However, it is only pos-
sible to measure the consequences of the stress relaxation rather than the
relaxation itself. One of the main destructive methods is to cut the cross sec-
tion into slices and measure the change in strains before and after cutting.
After measuring the strains, some simple analytic approaches can be used
to evaluate resultant membrane forces and bending moments in the cross sec-
tions. Although the testing procedures to determine residual stresses are out-
side the scope of this topic, it is important to detail how to incorporate
residual stresses in finite element models. It should be noted that in some
cases, incorporating residual stresses can have a small effect on the structural
performance of metals. However, in some other cases, it may have a consid-
erable effect. Structural steel cross sections used in bridges are subjected to
more loading conditions than that commonly applied to buildings. Since
the main objective of this topic is to accurately model all parameters affecting
the behavior and design of steel and steel-concrete composite bridges, the
way to model residual stresses is highlighted.
Limited numerical methods were presented in the literature to simulate
some typical and simple procedures introducing residual stresses. Dixit and
Dixit [
2.20
] modeled cold rolling for steel and gave a simplified approach to
provided the scope to investigate the effects of different parameters on
the magnitude and distribution of residual stresses such as material charac-
residual stresses and distortion of large steel shafts due to quenching. The
results showed that residual stresses are strongly related to the transforma-
water quenching of cylindrical solid steel bars of various diameters by using
finite element technique. The authors have computed the transient temper-
ature distribution for solid bars with general surface heat transfer. Jahanian
[
2.23
] modeled heat treatment and calculated the residual stress in a long
solid cylinder by using theoretical and numerical methods with different
lyze the transient temperature and residual stress fields for a metal specimen
during quenching. They modified the elastic-plastic properties of specimen
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