2.2.3 Operating Conditions
2.2.3.1 Environmental Factors
Regardless of the type of joining method ultimately selected, one of the most important considerations is the environment or surroundings to which the joint and substrate materials will be subjected. Forces acting on the materials and assembly are important to consider. The selected substrates and joining method must carry the maximum expected load, resist fatigue or cyclic stresses and handle the operating conditions experienced during the operation.
Cyclic stresses, particularly slow ones, are more damaging to materials and joined assemblies than a steady stress. The substrates selected for a particular application must be able to resist these loads and stresses after sustained exposure and under any severe environmental factors encountered during the life of the assembly. Heat and humidity are common yet highly damaging environmental factors for many materials and joining methods.