Then we have some materials which follow this curve here, where it's,
it behaves essentially like a solid for slow rates of for
small stresses, but then begins to flow like a fluid.
And the material which follows that curve is called a Bingham Curve or
a Bingham Plastic or an Ideal Plastic.
And these materials are discussed in this sidebar in the FE Handbook.
However, we don't need to worry about all of these materials.
The only types of fluids that we will be concerned with here
are Newtonian fluids which follow this simple equation here and
fortunately, all of the fluids that we're interested in obey this relationship.
For example, oil, water, gasoline, air, et cetera, are all
Newtonian fluids so we don't have to worry about the more complex fluid behaviors.