That may seem like a simple question, but really, what is the difference between a material model and a set of material parameters? To start explaining this I think it is useful to first remember that a FE model simply uses three types of inputs:
- The geometry of all parts.
- The load and boundary conditions that are applied.
- The material models that describe the material behaviors.
Definition of "Material Model"
- Any product (such as a tire) will deform when exposed to a load. The amount of deformation depends on the stiffness of the material.
- A material model is an equation that relates the applied force (or stress) to the resulting deformation (or strain).
- All FE solvers support many material models, such as linear elastic, elastic-plastic, etc.
- The PolyUMod library contains additional material models that exhibit non-linear time- or strain-dependence (like most polymers).
Definition of "Material Parameters"
- A material model specifies the equation that convert between stress and strain for a material. A material model example is Linear Elastic.
- The material parameters are the numbers that specify the properties of a specific material.
- Example: At small deformations, both steel and rubber can be approximately linear in their stress-strain response. That is, both can be represented using a Linear Elastic material model, but they have very different material parameters (such as stiffness).
- The MCalibration software makes it easy to convert experimental data into a calibrated material parameters for a given material.