Safety factor thresholds
For static stress studies, safety factor thresholds (also called targets) define the acceptable range for your design. These thresholds help you interpret safety factor results and identify areas that need attention.
Default thresholds
The default safety factor thresholds are:
- Lower Target: 2.0
- Upper Target: 4.0
Color-coded result zones
Results are color-coded based on these thresholds to provide immediate visual feedback:
Below lower target (red): Safety factor < 2.0
This is a critical warning indicating that the current design may bend or break as a result of the applied loads and constraints.
- Areas with safety factor < 1.0 will experience some sort of failure (either permanent deformation or breakage)
- These areas require immediate design changes to strengthen the structure
- Use Below Target visualization to focus exclusively on these critical regions
In range (green): Safety factor between 2.0 and 4.0
This is a preliminary indication that your design is suited for the application.
- The design has adequate safety margins for most general applications
- Material is used efficiently without excess
- A well-balanced design should have most areas in this range
Above upper target (blue): Safety factor > 4.0
This indicates the current design appears to be over-engineered.
- Areas have more structural capacity than required
- Opportunities exist to reduce material, weight, or cost without compromising safety
- Use Above Target visualization to identify optimization opportunities
Industry variations
Different industries have different safety factor requirements. The default thresholds work for general purposes, but your industry may require different values:
- Some industries accept lower safety factors (< 2.0) for specific applications
- Aerospace, pressure vessels, and crane industries often require higher safety factors
- Consider dynamic loads, fatigue, material reliability, and failure consequences when determining appropriate thresholds
- Warning: Reducing the upper target can give a false positive indication when your design may not actually be adequate
Note: Autodesk cannot dictate what safety factor you should achieve. Research safety factor guidelines for your industry and ensure compliance with applicable codes and standards.
Customizing thresholds
You can customize the thresholds to match your industry requirements or specific application needs. When you modify the thresholds, the color zones adjust to reflect your custom range.
For information about changing thresholds, see Change safety factor thresholds.