The Beam config has 2 subtypes: Beam_member and Beam_shell. The first is made of 1D
                elements while the second points to freebody sections. Both configs come with their
                flavor of the same actual methods:
                    - Stringer Axial Stress
- Stringer compressive buckling
The Stinger Axial Stress is a simple method which calculates the Compressive/Tensile
                margin of safety as:
            MS= [(Compressive Stress limit)*(section Area)/(Axial Force)] -1; (resp. Tensile
                Stress limit)
            In the case of freebody sections, Axial Force is mapped to the freebody resultant
                Fx.
            The compressive buckling method evaluates 
                        
                     with:
                        - 
                                
                            : average axial stress as (Axial
                        Force)/(Section’s area)
- 
                        
- 
                                
                            : material compressive stress limit
- 
                                
                            
                            - K_constraint = “constraint coefficient” on structural property.
                                Def=0.0699
 
- 
                                
                            : beam section’s radius of gyration
- E: material young’s modulus