By changing the location of the vibration on a circular Chladni plate, I found that the patterns change for the same frequencies at which the plate was vibrated from the centre. What effect does the source point of vibration have on the characteristics of standing waves produced in the Chladni plate?
At the position of the vibrating source the amplitude of the oscillation of the palte at that position is fixed by the amplitude of the vibrating source.
So with source in one position there may be a node at another position on the plate. Moving the source to the position where there that node was before would mean that it was no longer a node and so the pattern generated would be different.