For an example of destructive degradation, open the Adhesive Bond B.jmp data table in the Reliability folder of Sample Data. The data consists of measurements on the strength of an adhesive bond. The product is stressed until the bond breaks, and the required breaking stress is recorded. Because units at normal use conditions are unlikely to break, the units were tested at several levels of an acceleration factor. There is interest in estimating the proportion of units with a strength below 40 Newtons after 260 weeks (5 years) at use conditions of 25o C. Follow the steps below to do the destructive degradation analysis.
1.
Open the Adhesive Bond B.jmp sample data table, located in the Reliability folder.
2.
Select Rows > Clear Row States to clear the excluded rows.
3.
Select Analyze > Reliability and Survival > Degradation.
4.
Select Newtons and click Y, Response.
5.
Select Weeks and click Time.
6.
Select Degrees C and click X.
7.
Select Status and click Censor.
8.
Type Right in the Censor Code box. This is the value in the censor column that identifies censored data.
9.
Select Destructive Degradation from the Application menu.
Completed Launch Window
Note there is no variable assigned to the Label, System ID role. That role is used in regular degradation analysis when the same unit is measured multiple times. In destructive degradation, each unit is measured once, so each row of the data table corresponds to a different unit, and there is no need for an ID variable.
10.
11.
Select Lognormal from the distribution menu (under Location Parameter Path Specification).
12.
From the platform red triangle menu, select Degradation Path Style > Nonlinear Path.
13.
Select Constant Rate from the menu beneath where you selected Lognormal.
No Transformation for Path Transformation.
Arrhenius Celsius for Rate Transformation.
Sqrt for Time Transformation.
15.
16.
Click Use & Save.
17.
Click Fit Model. The fitted lines for the model are shown in Plot of Model.
Plot of Model
18.
Select Generate Report for Current Model.
Distribution Profiler Results