Premium
Fatigue under complicated load histories. Law of cumulative damage
Author(s) -
Prevorsek Dusan C.,
Brooks Michael L.
Publication year - 1967
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1967.070110613
Subject(s) - law , materials science , structural engineering , mechanics , statistical physics , forensic engineering , physics , engineering , political science
The applicability of Miner's law of cumulative damage to predict lifetimes in experiments involving complex load histories is examined. Lifetimes estimated by Σ t i /( t b ) i = 1 are compared with those calculated by the expression for the time to rupture derived by Prevorsek and Lyons assuming that the time to rupture can be approximated by the time to form an unstable crack. For experiments in which the loading conditions became increasingly severe with time, lifetimes predicted by Miner's law are longer than those calculated from the rate of crack propagation, the opposite being found for experiments in which the loading conditions become decreasingly severe with time. Experimental data on hand are in agreement with these findings. Effects of changes in the structural parameters ρ, E , and Δ F * and of variations in the experimental conditions on the accuracy of the lifetime estimates are discussed.