37 different mechanical fatigue definitions

In this document are showed 37 different definitions of the mechanical fatigue phenomenon. The definitions were obtained from the review of some bibliographic references.
To develop the work, several documents on the topic of fatigue were consulted. 38 references were selected because they included a definition of mechanical fatigue.
With the 37 selected definitions, a binary matrix was created in Microsoft Excel software, in which the authors are located in the rows and the different factors used by them in the columns. A total of 49 factors were identified that, according to the different definitions of fatigue studied, can influence the phenomenon.