I’ve been working on the vehicle subframe design.
So far, it uses primarely steel retangular hollow sections and C channels. That seems to be a good balance between load and weight.
The current design is quite beefy, handling up to 20tons without any major displacement. It is by far stiffer and stronger than any 18ton truck chassis.
Next steps will involve designing the 4-point mount; and modeling the truck chassis for torsion analysis. With that data, it might be possible to optimize the subframe to reduce weight or welding points.