Beam Failures

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

$M S = F_{c c} / σ_{x} - 1$ with:

$σ_{x}$ : average axial stress as (Axial Force)/(Section’s area)
$F_{c c} = F_{c y} * (1 - .272 (L' / ρ) / π * \sqrt{E / F_{c y}})$
$F_{c y}$ : material compressive stress limit
$L' = (structural property L e n g t h) / \sqrt{K_constraint}$
- K_constraint = “constraint coefficient” on structural property. Def=0.0699
$ρ$ : beam section’s radius of gyration
E: material young’s modulus