Template:Stress-Strength Analysis in Design For Reliability

Stress-Strength Analysis in Design for Reliability
As we know, the expected reliability is called from the following stress-strength calculation:

$$R=P[Stress\le Strength]=\int_{0}^{\infty }{{{f}_{Stress}}(x)\cdot {{R}_{Strength}}(x)}dx$$

The stress distribution is usually estimated from customer usage data, such as the mileage per year of a passenger car or the load distribution for a beam. The strength distribution, on the other hand, is affected by the material used in the component, the geometric dimensions and the manufacturing process.

Because the stress distribution can be estimated from customer usage data, we can assume that $${f}_{Stress} $$ is known. Therefore, for a given reliability goal, the strength distribution $$ {R}_{Strength}$$ is the only unknown in the given equation. The factors that affect the strength distribution can be adjusted to obtain a strength distribution that meets the reliability goal. The following example shows how to use the Target Reliability Parameter Estimator tool in the stress-strength folio to obtain the parameters for a strength distribution that will meet a specified reliability goal.

Example 2: