How to Specify Material Properties with Functions in COMSOL Multiphysics

You can define an Analytic, Interpolation, or Piecewise Function to describe any material property in COMSOL Multiphysics. Defining a function for a material enables the software to approximate the value of the material property through the duration of your simulation. Interpolation Functions are used to fit an expression to data defined at discrete points, such as measurements. Enter the data manually or import it from a file. Next, choose how the function behaves both between and outside of your data points. Analytic Functions are used to implement a variable-dependency to a material, like a temperature and/or pressure-dependent property. You can enter your equation and then specify the arguments within the expression. Piecewise Functions are used to add a function that has different definitions on different intervals. For each interval of values, you can specify a Start and End value as well as the function applicable to that range of values.