Safety factor result
All objects have stress limits that are dependent upon their construction material. Safety Factor is an important result that you can use to evaluate how suitable a design is for its intended application. The safety factor indicates if a design is likely to survive unharmed, bend, or break when subjected to the applied loads. There are various criteria and considerations influencing what the safety factor should be for a given material, manufacturing process, and application.
The Safety Factor result is produced by the following study types:
- Nonlinear static stress
- Static stress
- Thermal stress
Frequently, designers strive for a minimum safety factor between 1.5 and 6, depending on the application. Design safety factor compliance is based on the greatest expected loading scenario. However, lesser or greater safety factors might be targeted in certain cases.
Design safety factors typically exceed 1.0 by a significant margin. A safety factor less than 1 indicates that some sort of failure will occur (either permanent deformation or breakage). A safety factor of exactly 1.0 means that the actual stress equals the material strength limit, so the design is on the verge of failure.
The plot legend for Safety Factor results defaults to a range of 0–15. Also, an extra tick mark, numeric value, and the abbreviation Min in the legend scale indicates the actual minimum safety factor result. For example, the following legend indicates that the worst safety factor result is 3.4:
to adjust the legend range and therefore the color contours. For example, you might want to set the minimum value to 1 instead of 0 so that any marginal areas are definitely red. Alternatively, you might want to set the minimum value to the actual minimum resultant safety factor indicated in the legend scale. This option would render the minimum safety factor areas of the model red regardless of the magnitude, making the critical regions easy to find. Finally, if the actual maximum safety factor is significantly less than 15, you might want to decrease the specified maximum legend value. This action produces a greater spectrum of result colors. Otherwise, the maximum safety factor areas will not be rendered in dark blue. You might want to force all results above a particular value (for example 6) to appear as dark blue, indicating that you consider these areas to be safe. Specify the maximum legend value accordingly. The following image shows the analysis results as the previous image but with the minimum legend value set to 3.4 and the maximum set to 10. (Since the maximum value output by the software is beyond the specified range, the label Max.: 15 is added beneath the legend):
If a limited area of a design goes into yield, it does not necessarily mean that the part will fail. However, if the maximum expected load is frequently repeated or a relatively large percentage of the part volume yields, failure is likely. Use engineering principles and experience to evaluate each situation. Also, see the Factors Affecting the Choice of a Design Safety Factor page.