Day: November 19, 2016

Factor of safety

Factor of safety

Factor of safety

11/19/16

“How do engineers deal with loads near the failure point?”

 

When doing engineering, one has to deal with the maximum load that a system can handle. However, in the real world, it would be quite unwise to have loads even near this limit. The rationale behind this is that such a system could experience an unexpected impingement. To illustrate, let’s suppose that enough people stand in an elevator to have it at maximum capacity, if even a rat were to climb into this elevator, then this capacity would be overloaded and the elevator would experience failure. Luckily, engineers tend to be foresightful people, so when developing structures, instead of designing them just to sustain the expected loads, they are created in respect to a factor of safety. A factor of safety an extra “margin” that a structure can support (in terms of a multiple of the expected load), and can be calculated using the formula FoS =Ultimate stress/actual stress . An example of the factor of safety in use is the famous Eiffel tower, which is designed to sustain 4.5 times as much stress than it typically does. In summation, the factor of safety is an intrinsically necessary tool in modern engineering, and has saved countless of lives all over the world.