Editing Failure cause (section)

==Types of failure causes==
===Mechanical failure===
Some types of mechanical failure mechanisms are: excessive deflection, [[buckling]], [[ductile fracture]], [[brittle fracture]], [[impact (mechanics)|impact]], creep, relaxation, [[thermal shock]], [[wear]], corrosion,<ref>While corrosion is not technically a mechanical failure mode, it is usually included in mechanical failure modes because it leads directly to mechanical failures.</ref> stress corrosion cracking, and various types of fatigue.<ref>{{Cite book|url=https://books.google.com/books?id=B2aAPVa1TloC|title=Metal Fatigue in Engineering|last=Stephens|first=Ralph I.|last2=Fatemi|first2=Ali|last3=Stephens|first3=Robert R.|last4=Fuchs|first4=Henry O.|date=2000-11-03|publisher=John Wiley & Sons|isbn=9780471510598|language=en}}</ref> Each produces a different type of fracture surface, and other indicators near the fracture surface(s). The way the product is loaded, and the loading history are also important factors which determine the outcome. Of critical importance is design geometry because [[stress concentrations]] can magnify the applied load locally to very high levels, and from which [[Fracture|cracks]] usually grow.

Over time, as more is understood about a failure, the failure cause evolves from a description of symptoms and outcomes (that is, effects) to a systematic and relatively abstract [[model (abstract)|model]] of how, when, and why the failure comes about (that is, causes).

The more complex the product or situation, the more necessary a good understanding of its failure cause is to ensuring its proper operation (or repair).  [[Cascading failure]]s, for example, are particularly complex failure causes. [[Edge case]]s and [[corner case]]s are situations in which complex, unexpected, and difficult-to-debug problems often occur.

=== Failure by corrosion ===
Materials can be degraded by their environment by [[corrosion]] processes, such as [[rusting]] in the case of [[iron]] and [[steel]]. Such processes can also be affected by load in the mechanisms of [[stress corrosion cracking]] and [[environmental stress cracking]].