fluid-membrane interaction problem
 

Hello
Everyone, I am now doing two way fluid-membrane interaction simulation with Ansys Workbench, the membrane is given uniform and constant pretension everywhere. However, I don't know how to define the pretension of membrane,
I don't know how to do the two way fluid-solid interaction with pretension,either, because all the tutorials are the cases without pretension. So could anyone help me to figure it out. Thanks very much.