private scholar, Germany
Title: Relation between internal friction and fatigue
Biography: Wolfgang Gräfe
The background of internal friction in solids and their fatigue may be theoretically described by a migration of unspecified items which is caused by the action of mechanical stress gradients. From the two resulting formulae a relation between the fatigue and the background of internal friction has been deduced. With this relation the statistical distribution of the fatigue data can be explained to some extent. Data published by Ravilly in 1938 demonstrates the correctness of this theoretical result. For the case that temperature gradients are the reason for the migration of the unspecified items, a formula results which is similar to the above mentioned one for the fatigue. With the statistical analysis of the data for fatigue and the total internal friction it could be possible to answer the question which physical quantity is the cause of fatigue.