Given stress-strain data from experiments for a specific material, engineers usually do curve fitting to find out the parameters needed for a hyperelasticity model. These parameters will be used to fully describe the stress-strain relationship. However, what if the stress-strain data we have in hand is uniquely complex and cannot be well captured by the conventional strain energy density functions? In this lesson, we introduce the response function feature provided by Ansys, which is an alternative to the curve-fitting method for modeling hyperelastic materials.
6:19 - Initially 1st order Yeoh model (a.k.a. neo-Hookean model) is shown, but at 6:19, a curve-fit using Ogden model is shown. The fact that two different curve fits are shown is not made clear in the video.
7:32 - Equation for sigma_33 shown is incorrect where lambda_1 term should be raised to 4th power rather than 2nd power (both terms)
Download the accompanying geometry and archived files here. The student version of Ansys simulation software can be downloaded here.