BACKGROUND - Introduction
Brittle materials such as ceramics exhibit significant scatter in tensile strength, thus probabilistic design approaches must be utilized when designing components fabricated from brittle materials. Accounting for the inherent scatter in tensile strength phenomenon requires a change in philosophy on the design engineer’s part that leads to a reduced focus on the use of safety factors in favor of reliability analyses. If a brittle material with an obvious scatter in tensile strength is selected for its high strength attributes or inert behavior, then components should be designed using an appropriate design methodology rooted in statistical analysis. However, the reliability approach demands that the design engineer must tolerate a finite risk of unacceptable performance. This risk of unacceptable performance is identified as a component's probability of failure (or alternatively, component reliability). The primary concern of the engineer is minimizing this risk in an economical manner.