The Mechanical Design Team working to validate the mechanical design structure of 4WD robot before manufacturing, it is a very important step to avoid losing time and money.
After confirming the dimensions of robot and select the suitable structure shape, designers supposed to select a proper material suitable with the forces applied on the robot and available on the local market.
The team uses a different CAD software to validate the design and avoid any losses, when applied the forces on the structure it will be easy to detect where is the position of maximum stress and what is the value of maximum stress.
Now the designers will be happy when the maximum stress is less than the yield strength of the material and take a factor of safety in consideration, it is valid.
Otherwise they need to recalculate the study by change the material or design a new support parts on the maximum stress position.
Also it is very important to take in consideration the maximum deformation happened in case of maximum force applied "for sure this is an elastic deformation where the part will return to the original dimensions after release the load".
Good Luck!!