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                                                                               FILE                DATE
                                                                               CODE                November 11, 1969
                                         DEPT-   Special
      TO - NAME                                                       DIVISION               PLANT/OFFICE
                  H. P. Bruns               Vehicle Development         Engineering Office        Highland Park
      FROM - NAME                                                     DIVISION               PLANT/OFFICE
                                         DEPT-    Circuit
                  W. P. Wright           Racing Vehicle Operations       Space                    Huntsville
                  Analysis of Vibration Data From Talladega Test

   References:    1.      Human Performance During Vibration. Charles S. Harris, Aerospace
                          Medical Research Labs., Wright-Patters on A FB, Ohio, AMRL-TR-65-204,
                          November 1965.
                  2.      Human Reactions to Vibration and Impact. David E. Pettijohn, Boeing Company
                          Seattle, Washington, January 1960.
                  3.      Effects of Low Frequency High Amplitude, Whole Body, Longitudinal and Trans­
                          verse Vibration Upon Human Performance. Richard J. Hanhick, Charles H.
                          Boettcher, and Allison K. Simons, Boston Research Labs, Milwaukee, Wisconsin,
                          July 1961.
                  4.      Shock and Vibration Handbook . Edited by Cyril M. Harris and Charles E. Crede,
                          Columbia University and California Institute of Technology, McGraw-Hill Book
                          Company, Inc., 1961.

                          The vertical and lateral acceleration data recorded on 1/2 inch magnetic tapes
                  during the tire tests at Talladega, 20-25 August 1969, indicated that the induced vibration
                  environment may be of a frequency such that it will couple with the natural frequency of
                  some body organs. This data further indicated that the amplitude of the peak accelerations
                  may be sufficient to produce undesirable physical reactions. Visual analysis of the data
                  stripped out on the Brush pen recorder confirmed that all the factors were present. It is
                  however, not practical to correlate completely such data by hand or direct visual methods.

                          A portion of the data recorded during tire tests has, therefore, been analyzed
                  digital computer techniques- Fast Fourier Transform -to achieve a comparison with            the
                  best known human vibration criteria. Those portions of the data selected for analysis         are
                  given in the following table:

                                 Test No.        Turn #1       Turn #2      Straightaway

                                    19           1, 2, 3        1, 2, 3          1, 2

                                    21           1, 2           1, 2


                          1  - vertical acceleration
                          2  - lateral acceleration
                          3  - left rear suspension displacement.

       84- 110-7879 REV. 1-63
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