Design and Stress Analysis of Extraterrestrial ... - The Black Vault

Analysis of the disk using the two calculation method is
presented in Table 3.3. In the first calculatior stresses in the center
of the disk are given as a ' = 2000 daN/cm 2 and in the second
calculation rOl = Ot= 100 daN/cm . Figure 3.55 gives graphs
showing the variation in stresses or and a9 along the radius of
the disk.
4 4 250 400 550 t 0 C
4 ( 6 1fc
2 2N
I/ I I
-4000 -36000-2000-1000 0 WOO0 ?000 JO000 4000
6daHicM2 (1)
Fig. 3.55. Shape of turbine disk, stresses and temperature
distribution in it along the radius (example of calculation).
KEY: (1) daN/cm 2 .
Stress analysis of disks by the integral
method
The earlier examined method of analyzing disks is the most
accurate. However, nomograms for determining coefficients a and
0 are plotted only for one value of the Poisson coefficient u = 0.3
while its value in the temperature range of the turbine disk can
vary from 0.3 to 0.11 (maximum possible value of the Potsson coefficient
with plastic flow is umax = 0.5).
Although the effect of p on the value of stresses is not very
great, nevertheless sometimes it is necessary to calculate for the
values of P X 0.3, for example, when analyzing a disk with allowance
for plastic flows (see below).
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