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Circular Plate - Free


A circular plate unattached at its edges.

(make-object 'free-circ-plate ... )

Syntax and Default Values

A 'free-circ-plate can be created using the following Lisp syntax (the default values are shown for each of the physical parameters):

(make-object 'free-circ-plate
             (modes 80)
             (radius .5)
             (thickness .01)
             (density 7800)
             (young 2e11)
             (poisson .3)
             (freq-loss 1) 
             (const-loss 1))


The arguments for the physical parameters can be either numerical values or Modalys controllers (either dynamic or constant). If a given parameter is not supplied when using the Lisp syntax, the default parameter value will be used.

  • modes: number of modes.
  • radius: in meters.
  • thickness: in meters.
  • density: in kg/m3. See chart of material properties for appropriate values.
  • young: Young's modulus, in N/m2. See chart of material properties for appropriate values.
  • poisson: poisson ratio. See chart of material properties for appropriate values.
  • freq-loss, const-loss: loss coefficients. See General object information.


A 'free-circ-plate can be accessed in one dimension - perpendicular to the plate (i.e. 'normal):

(make-access my-plate my-2D-controller 'normal)
The first dimension of my-2D-controller is a number between zero and one which describes the distance from the center of the plate to the edge (zero is at the center and 1 is at the edge). The second dimension describes the angle (in degrees) of the radius in question. If there is only one access, then, this dimension is of no importance and can be left at zero. If the plate has several accesses, the angle is used to describe the relationship between them.

(make-access1 my-plate (const 0.25 0) 'normal)
(make-access2 my-plate (const 0.75 90) 'normal)



A 'free-circ-plate can be tuned to a specific pitch, using the (set-pitch ...) function, by adjusting one of the following physical parameters:

  • 'radius
  • 'thickness
  • 'density
  • 'young

For example:

(setq my-plate (make-object 'free-circ-plate))
(set-pitch my-plate 'radius (const 440))

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