Dear Thank you very much for spending your time. the words can not describe your favor. I hope I can get my result and my mind will be in peace.
1.yes, I used nonlinear material (Bilinear Isotropic hardening) and defined all the required data. I set large deflection ON
2..I did not do mesh convergence very carefully but how we can change the mesh near the high-stress region? In this type of structure (like scaffolds) there are a lot of sharp corners or holes or maybe thin walls, I think it would be very time-consuming to do that manually and I also do not know how to do that. I can search or if there is any link to share with me, it would be great for me to learn.
3.actually, I tested it before with a tangent modulus of 0 but unfortunately, the result was the same, and nothing happened just the region after yield was dropped down and I still had this curve without any sharp corner . then I switch on using 1.25 GPa but I so nothing happened. just the region after yield was fitted on the paper result but the elastic region still has problem, It seems some point in this area have been lost and ANSYS can not simulate their behavior ( I guess it)

4.Peter, but the slope of my solution does not match with the paper. this slope is the modulus of elasticity of scaffold and it is so important thing that should be considered always and there is a huge difference between my result and this paper. they computed it around 8 GPa and for me, it is around 13 GPa! (a huge difference, with a huge error. The error should be around 2 or 3 )
analysis setting
Connection setting for both plate and scaffold ( I used frictional instead of frictionless contact because my scaffold was sacaped during the simulation, I know the frictional contact has effect on the result but how could constraint my scaffold to prevent moving in frictional contact? )

I used this connection setting according to help and documentation of ansys for rigid body-flexible contact. I hope they are correct.
Dear Peter, thanks again.