Getting 3D Voronoi structure as a step(.stp) file for FEA software like ANSYS

As it looks in the image I have attached, I was able to generate a voronoi diagram structure. But while saving the file from Rhino 5.0 as '.stp'(step) file or '.igs'(iges) file the only geometry that is converted is box or points that has been created in rhino before generating voronoi structure by grasshopper.

What can I do if I want to export the same 3D solid plate like structure (Divided in different solid cells) as it is visible in the image for further analysis purpose in external FEA tools(i.e ANSYS/ABAQUS)?

Thanks for all the help you guys are doing by posting different problem solutions.