Page 5 - Mechanical design of microresonators _ modeling and applications
P. 5

0-07-145538-8_CH01_4_08/30/05



                                            Design at Resonance of Mechanical Microsystems

                              4   Chapter  One




                              paddle cantilever






                                                                  anchor

                              translatory motion
                              Figure 1.4 Microcantilever as a single-degree-of-freedom system.

                                m
                                       x


                              k


                              Figure 1.5 Single-degree-of-freedom mass-spring system.

                              The solution to Eq. (1.3) is
                                                   .
                                                   x
                                             x(t) =  0  sin(Ȧ t) + x cos (Ȧ t)            (1.4)
                                                   Ȧ r    r     0     r

                              where the natural (or resonant) frequency is
                                                             k
                                                      Ȧ =                                 (1.5)
                                                        r    m
                              and the initial displacement and velocity conditions are
                                                         dx         .
                                                x(0) = x    |     = x                     (1.6)
                                                       0  dt  t =0   0

                                Similarly, the equation of motion of a single-DOF system formed of a
                              mass and a dashpot (mass-damper combination with viscous damping),
                              such as the one in Fig. 1.6, is
                                                     ..   .
                                                   mx + cx + kx =0                        (1.7)
                              and the solution to this homogeneous equation can be expressed as







                           Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
                                      Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
                                        Any use is subject to the Terms of Use as given at the website.
   1   2   3   4   5   6   7   8   9   10