Page 217 - Thomson, William Tyrrell-Theory of Vibration with Applications-Taylor _ Francis (2010)
P. 217

204                               Properties of Vibrating Systems   Chap. 6

                             6-30  In  a  manner similar to Prob.  6-2:9, show that
                                                               = 0,     1, 2, .
                             6-31  Evaluate  the  numerical  coefficients  for  the  equations  of  motion  for  the  second  and
                                 third  modes of Example 6.10-E
                             6-32  If  the  acceleration  ¿i(t)  of  the  ground  in  Example  6.10-1  is  a  single  sine  pulse  of
                                 amplitude   and  duration  /|,  as  shown  in  Fig.  P6-32,  determine  the  maximum  q  for
                                 each  mode  and  the value  of   given in  Sec.  6.10.







                                                                    Figure P6-32.

                             6-33  The  normal  modes of the  double pendulum of Prob.  5-9 are given as
                                                  o>|  =      ,   ft»2  =  1-850-y/j

                                                               0.707 \
                                                  4> i          1.00   / ’
                                                          (1)
                                                                -  0.707 \
                                                                 1.00  /
                                 If the  lower mass  is  given  an  impulse   determine  the  response  in  terms  of the
                                 normal  modes.
                             6-34  The  normal  modes  of  the  three-mass  torsional  system  of  Fig.  P6-6  are  given  for
                                 /,  = ^2 = J3  and  K^=K^ = K^.
                                                      (0.328 \       J(i)\
                                                    =  0.591  ,      ~k~  0.198,
                                                      (0.737)

                                                      1 0.737
                                                 4 > 2  =  0.328     1.555,
                                                      i  -0.591
                                                      (   0.591
                                                    =  -0.737        3.247
                                                         0.328
                                 Determine  the  equations  of  motion  if  a  torque  M(t)  is  applied  to  the  free  end.  If
                                 M(t) = M(^u(t), where  w(r) is a unit step function, determine the time solution and the
                                 maximum  response of the  end  mass from  the shock spectrum.
                             6-35  Using  two  normal  modes,  set  up  the  equations  of  motion  for  the  five-story  building
                                                                                      ,
                                 whose  foundation  stiffness in translation  and rotation  are  A:,  and   =  00 respectively
                                 (see  Fig.  P6-35).
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