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Equations of Motion in Cylindrical and Spherical Coordinates 191

         and A is a constant. Verify that the given state of stress is in equilibrium in the absence of body
         forces.
           Solution. From R = r + z , we obtain




         Thus,














         Thus, the left hand side of Eq, (4.8. la) becomes, with B r = 0




         In other words, the r-equation of equilibrium is satisfied.
           Since T& = TQ Z = 0 and TQQ is independent of 0, therefore, with BQ — a@ — 0, the second
         equation of equilibrium is also satisfied.
           The third equation of equilibrium Eq. (4.8. Ic) with B z — a z = 0 can be similarly verified.
         [see Prob. 4.35].



         Spherical coordinates
















        Again, we note that for symmetric stress tensor, T^- T0 r = 0 and7^- 7^=0.
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