Civil Engineering Reference
In-Depth Information
Table 5.2
Specific heat
values at temperatures
reached during testing
(SS304 and Ti-G5)
Material
Description
Temperature (°C)
C
p
(J/kg
°C)
Conv.
30
475
SS304
EAF
250
503
500
530
Stationary
Conv.
30
544
Ti
450
650
EAF
800
690
Stationary
Fig. 5.16
Specific heat
sensitivity (Ti-G5) [
11
].
Thermal profiles of stationary
electrical tests with specific
heat values for particular
temperatures
Conv. (30
o
C)
EAF (450
o
C)
Stationary (800
o
C)
each type of tests was considered, in order to observe the maximum variability in
the results due to variation of
C
p
with temperature.
To analyze the sensitivities of the specific heat value, stationary electrical tests,
where a non-deforming static load is applied to the workpiece and a constant elec-
trical power is applied, were simulated using the previously developed thermo-
mechanical predictive model [
1
]. Figure
5.16
displays the thermal profiles for
stationary electrical tests with specific heat values representative of maximum tem-
peratures witnessed during conventional, EAF, and stationary electrical tests for
Ti-G5. Additionally, Fig.
5.17
displays the same information for Stainless Steel 304.
When comparing the two figures, one can see that the specific heat of the Ti-G5
material was more dramatically affected, and this resulted in a larger variation in
the specimen thermal profiles when using the three different specific heat values.
At one point, the difference in the temperature profiles of the three tests for Ti-G5
was about 50 °C, whereas the maximum difference between the three tests for
SS304 was about 15 °C. One possible reason for this is the intrinsic specific heat
property of the material and its relationship with temperature (Fig.
5.15
), coupled
with the temperatures reached during testing. The black dots in the figure repre-
sent the maximum temperature reached for each material. The temperature range
reached for the Ti-G5 (0-800 °C) produced a 30 % increase in the metal's specific
heat value as the temperature was increased. In comparison, the temperature range
reached for the SS304 (0-500 °C) produced a 12 % increase in the specific heat
