5. The bending moments were calculated about the radial location of 
the strain gages on the flexures, rather than about the shaft axis or some 
desired radius on the blade. 
Final analyses were conducted after completion of the experiment to 
consider interactions, to filter out extraneous high frequency noise, to 
isolate hydrodynamic loading from centrifugal and gravitational loading, 
to correct for the dynamometer boat, and to resolve bending moments as 
desired. These analyses were conducted using a Control Data Corporation 
(CDC) 6700 Computer. 
For each condition, the average wave form for each of the six load- 
ing components was multiplied by the inverse of the calibration matrix 
given in Table 2. 
FAA ar 
Oo Bt 
Bon Mg FYI E IF 
Mn Mey oo 
FA z1 
MA a 
This matrix multiplication was performed at 4-degree increments of blade 
angular position. 
An harmonic analysis was then performed on the signals corrected for 
the interactions. Based on an harmonic analysis of the wake in the pro- 
peller wile, it was judged that there should be no significant loading 
of hydrodynamic origin at frequencies above ten times shaft frequency. 
Therefore, the wave form was then reconstructed by using the first ten 
harmonics of shaft frequency. This reconstruction using only the first 
ten harmonics had the same effect as filtering out all frequencies above 
ten times shaft frequency. 
Cecmtincss D.E., "Numerical Prediction of Propeller Characteristics," 
Journal of Ship Research, Vol. 17, No. 1, pp 12+18 (March 1973) 
20 
