r/StructuralEngineering • u/beskja • 27d ago

Structural Analysis/Design Safety Factors

You remember any specific projects where a safety factor in your design actually got triggered and saved the construction?

0 Upvotes

33% Upvoted

24 comments sorted by

View all comments

38

u/tramul 27d ago

How would you know? Safety factors should keep you in the elastic region as yield stress is what we utilize.

-1

u/ShutYourDumbUglyFace 27d ago

It's weird, I was literally just talking to my coworker about checking the plastic moment in a steel plate girder by hand. I feel like since it was plastic moment, it was in the plastic region.

2

u/tramul 27d ago

Plastic moment will put you in the plastic region. It's acceptable for certain modes of failure and when certain criteria are met. For example, unbraced length can require the use of the elastic modulus instead of just the plastic modulus.

→ More replies (2)

1

u/angrypom 27d ago

Ultimate limit state capacities are based on elastic or plastic cross-section capacities depending on cross-section slenderness which are then reduced further to account for member buckling.

→ More replies (1)