Page 135 - Mechanics of Microelectromechanical Systems
P. 135

122                                                         Chapter 2
         Solution:
             By applying  Castigliano’s  displacement theorem,  the  deflection and
         slope at point 2 can be calculated as:









         which indicates that the compliances are:











         and therefore,  each of these  compliances has  the  general form of the  full-
          length compliances given in  Chapter 1, but they are calculated  for half the
          length. They can be expressed in terms of the compliances corresponding to a
          microcantilever of length l as:










             Returning to the generic microbridge of Fig. 2.39, the unknown reactions
              and     are  first determined  by  applying Castigliano’s  displacement
          theorem and the zero deflection and zero slope boundary conditions at point
          1. The reactions are of the form:







          where the constants   and   are calculated as:








          The coefficients of Eqs. (2.194) depend on the compliances of the individual
          portions 1-2, 2-4 and 4-5 in the form:
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