Thank you, sir, for the reply,

It is for the electric scooter, and the battery casing will be welded to the chassis. Total mass is expected to around 255 kg including rider and pillion rider.

Should I need to model the suspensions? because that is not my area of interest. is there a way to connect it to wheels.

I looked about mid surface models, this is applicable only when all tubes have the same thickness. But mine it is not the same case.