Page 201 - Handbook of Adhesives and Sealants

Standard Test Methods 171

Figure 4.23 Testing hierarchy as illustrated by the ‘‘Mathes ladder’’. 23

cesses which will help to guide the engineer toward systematically
getting the information required.

1. Define extent of service condition variables (upper limits of condi-
tions to be encountered).
2. Identify specific failure mode(s).
3. Determine rate of damage for each failure mode at the extreme
service conditions.
4. Define critical failure mode.
5. Establish endurance limit of the system.
6. Determine reliability of endurance limit value(s).
7. Plan margin of safety for engineering design from established en-
durance limit.

The testing and characterization of adhesives or sealants is a key
to their successful application. However, testing must be combined
with understanding of the principles of adhesion and the many pro-
cesses that are involved.