Stress-Strength Analysis in Design for Reliability

Stress-Strength Analysis for Determing Strength Distribution

Assume the stress distribution for a component is known and it is a Weibull distribution with beta=3, and eta=2000. For the current design, the strength distribution is also a Weibull distribution with beta =1.5 and eta=4000.

• Evaluate the current reliability.
• If the reliability does not meet the target reliability of 90%, please use the Target Reliability Parameter Estimator to determine what parameters would be required for the strength distribution in order to meet the specified target.

Solution

First, we need create two empty Weibull++ standard folio and enter the distribution parameters for the stress and strenght distribution. For example, for the stress distribution, it is:

Then, following the steps given in Example 1, the reliability of the current design is given in the following figure:

The above result shows that the current reliability is about 74.05% which is below the target value of 90%.