Version 1.0, August 31, 2001, Copyright, Hugh Jack 1993-2001

17.1 FACTOR OF SAFETY

 

· When we do basic design work we typically use a process of the basic format,

 

 

· In particular the design process often involves a factor of safety that allows for,

  1. - variations in material properties
  2. - variations in expectations load
  3. - the non-uniform distribution of stress
  4. - cyclic loading
  5. - etc

 

· The factor of safety is applied as,

 

 

· The values vary for various systems. The values given below are reasonable for static systems.

 

 

· For example let us consider a two member mechanism 1.44 from [Beer and Johnston]

 

 

 

 

 

 

17.1.1 Practice Problems