The solution follows Simpson's rule and
utilizes the discretization introduced for the
partial differential equation. The following
scheme is adopted for the integration:
The above transformation5 are automated
by the MeXeL, which generate
SPICE3 netlists from mechanics models.
These models are formulated as a set of
algebraic and non-linear (partial) differential
equations.
Example
Consider the simulation of a deformable
mirror device (DMD) and its controlling
circuit. The DMDs are deflectable mirrors
that are arranged in a matrix on the chip
[5,6]. Depending on the voltage at its electrode,
each DMD can be deflected separately.
In this way, the resulting phase or
amplitude modulation of incoming light can
be used to create a pixel image on a screen.
Various schemes have been proposed for
DMDs. Here, a simple, quadratic reflecting
plate is used. This plate is fixed on two sides
(Fig. 2).
For the upper plate, the following partial
differential equation is solved to calculate
the deflection:
a2u EI aJL4 w(x,t,U,li)
at2 PA ax' PA
+
E is the modulus of elasticity, I the moment
of inertia, r the density of the plate material,
A the cross-section of the upper plate and M'