Chapter-2-Factor of safety (FOF)

Factor of safety (FOF)

Factor of safety:-

Factor of safety is used to determine.
     

1. Permissible Stress 
2. Allowable Stress
3. Safe Stress
4. Working Stress 

                                          

Failure Strength:-

For Static Load ;

Yield Strength is the failure criteria for the Ductile Material
Ultimate Strength is the failure criteria for Brittle Material also Ductile Material

For Static Load;

Endurance Limit is the failure criteria.

Brittle:- 

Material will not permits any deformation and goes to fractures ultimate strength will be the failure strength.

Ductile:- 

• Case-1: When a material does not undergo permanent deformation or is under the elastic limit, yield strength will be the failure strength.

• Case-1I: When Material undergo permanent deformation, ultimate strength will be the failure strength.