what is the purpose of including safety factor in design?

Answer 1

as the name says "we are including a factor which takes care that the load for which we have designed our part and the part does not fail even if the load exceeds the load we have designed the part for". ex: if we want our part to take a load of 1000N and we have a Facto of safety as 1.5, then we are actually desinging the part to take a load of 1500N but restrictioning the load to 1000N for safety.

Answer 2

First, the analysis of structures is not precise and the strength properties of construction materials can vary from piece to piece. The designer must use the lowest expected values if he wants to be certain that his structure will stand.

Second, The loads that a structure will be submitted to are unknown. even though a code might give a design value of pounds per square foot for a residential structure, there is no way of predicting whether or not some one using the structure will stack up three or four pianos in one corner or a windstorm may occur that is several times more severe than anything on record. The designer, therefor, has to try to make the structure safe even for unusual loadings.

Third if a structure is designed right to the limit of the materials and the loads are precisely as designed for, the structure, while safe, would probably vibrate when someone walked across the floor. This may make people uncomfortable.

Answer 3

Normally whatever we design, we do it for Design conditions or parameters.
The operating as well as the design conditions or parameters are decided by the process or the working environment, which cannnot be guaranteed 100%.
Hence we consider some factor of safety over and above the design conditions and carry out the design. This takes care of any extra loads that may come above design conditions in some unwanted situations.
The factor of safety which we consider will increase the cost of the product or process, but that is the price which we should pay for the safety of the Process and the Personnel.
Normally the Factor of safety is very high in Civil Designs due to the high amount of uncertainities involved in the loading conditions.

Answer 4

Too much pride signifies ignorance! Take a deep breathe and look at both sides of the coin.

On one side it seems prudent to do so.

On the other, it looks like a waste expended for no purpose other than to cover for a big, a double, ignorance: (1) the users cannot really tell the limit of their uses, and (2) the designer does not truly know if the chosen materials and structures are sufficient.

Answer 5

to take care of extraneous factors.or to compensate for certain assumptions made during calculations

Answer 6

Many 3rd world countries don't bother.

Answer 7

To avoid lawsuits.


Doug