We do not currently have any Balsa materials in our database. I would recommend creating a new material in the "Foam" material family and then model the panel as a "Foam Sandwich". The failure modes and behavior of a balsa core panel I would expect to be very similar to those of a foam core panel. You will have failure modes such as wrinkling, core shear strength and shear crimping. The key thing is that the core is isotropic (as opposed to a honeycomb sandwich where the core has directionality).
You will have to enter the properties of the core material yourself. Directions for creating and entering new material properties can be found in the Material Manager User Manual.
