Page 247 - Steam Turbines--Design, Applications, and Rerating by Heinz-Bloch, Murari-Singh
P. 247
226 Chapter Twelve
segments by welding the shroud portions together. The effect of joining
the blades is allowed for mathematically by means of the bonding fac-
tor described later. Figure 12.5 shows how the dynamic loading on the
blades, i.e., the cyclic stress, can be drastically reduced by this segment
arrangement.
Figure 12.5 Vibration amplitudes of a control-stage blade due to
partial admission through nozzle segments A, C, and D: (a) individ-
ual blades; (b) groups of blades; y = deflection; y s = static deflection;
U = periphery. (Asea Brown-Boveri, Baden, Switzerland)
