Structural Design Philosophies?

[jnlbctln]

Good day!
I don't know if they are called Structural design philosophy but, can anyone enumerate(if the list is incomplete) and differentiate the :
1. Ultimate Strength Design
2. Working Stress Design
3. Limit State Design
4. Allowable Stress Design
5. Others (If there are)

Help please.. Thanks :)

 

[timthereaper]

I wouldn't call them philosophies, just structural criteria. A lot of those things are controlled by the intended operation for the task. Sometimes you want a widget just not to break, so you design to maximize ultimate strength. Sometimes there's a cyclical load on it, so you design for fatigue life. Sometimes you have a minimum limit for a widget under a certain loading condition. All of those terms are just different design parameters.