where A=A0 controls the magnitude of the oscillation relative to the magnitude of the initial shear, and xsd is the (nondimensional)
frequency of oscillation relative to the deviatoric relaxation time. We stress once again that inertial effects have
been ignored. Therefore in this application we must not choose the magnitude of xsd (the non-dimensional frequency) too
large; as this parameter increases, inertial effects will become more important. Imposing (29) with A ¼ 1; A0 ¼ 0:6 and
xsd ¼ 16p yields the displacement and subsequent shear stress fields as illustrated in Fig. 3. To avoid confusion, in this fig-