Step-by-step explanation:
A factor of safety is the load-carrying capacity of a system beyond what the system actually supports. Bridges, buildings, safety equipment, and fall protection all start with a factor of safety.
Simply put, the safety factor is how much stronger a system is than required. The factor of safety is the backbone of all structures and safety equipment and originates with engineers. In the planning phase of all structures and safety equipment, engineers determine the required overload from any object to remain safe in the event of an emergency.
For reliability, structures are typically built stronger than necessary. This is in case a structure experiences a heavier-than-expected load. This is a factor of safety. Ultimately, the amount of stress and overload a structure can handle comes down to the material used to build it.
Determining the factor of safety:
Engineers perform strength tests to determine how much weight a material can handle. Certain materials are more ductile than others, meaning they deform to pressure before breaking more so than others, like brittle materials. Brittle materials simply break once they meet the maximum force.
Ductile materials use yield strength to determine the safety factor. Brittle materials use the ultimate strength.
Yield strength: Determines the safety factor until the start of deformation.
Ultimate strength: Determines the safety factor until failure.
Ductile materials often test the factor of safety against yield and ultimate strengths while brittle materials usually only calculate the ultimate safety factor since the yield and ultimate values are often so close.
The necessary factor of safety of any structure determines the materials used. If a structure has a high required factor of safety, then engineers use a ductile material to build it. The realized factor of safety determines the amount of material used.
Required (design factor): A constant value imposed by law or standard. A structure is required to meet this value at a minimum.
Realized