ABSTRACT
This chapter discusses the concept of safety factors that are universally utilized in many branches of engineering. The main action of fuzzy logic is to extend formal considerations from exact world to real world, i.e., fuzzy logic makes it possible to take concepts, notions etc. which are well-defined, into the formal consideration. Every now and then somebody says that developing fuzzy systems and methods is revolutionary. The concept of safety factor is nearly universally applied in structural engineering. A fundamental problem of the strength materials, namely an element subjected to a tensile stress, is analyzed in the fuzzy sets’ context. Triangular membership function is considered for both stress and strength. Additionally, a structure possessing two failure modes is considered. However, as Norton writes, choosing the safety factor is often a confusing proposition for the beginning designer. The actual size of different examples of the “same” parts made in quantity may vary due to manufacturing tolerance.
