I am trying to do vibration analysis using ANSYS on automobile seat cushions as a part of my PG project. I already have a 3D model. But I am stuck in ANSYS. How do I assign material for the cushion in ANSYS. The cushion material generally used is Medium and High density PU foams with varying thickness. If I have to fit a model using curve fitting or Mooney Rivlin model, how do I get the parameters in those. Do I necessarily have to do experiments on the foams or is the experimental data available. Please provide reference..