Thank you for your reply. My supervisor suggested me to save it as a step file (.stp) and I couldnt find an option for that too.

I have one more problem, I also have to design bamboo with imperfections. One of them is ovality, in this model I am not able to create the outer rectangular part for the diaphram as it is in elliptical shape. I tried extrude also and it doesnt work. Could you please give me a suggestion to model that.

Thank you