Evaluating Component Fatigue Performance Under Programmed Random, and Programmed Constant Amplitude Loading

690050

02/01/1969

Event
1969 International Automotive Engineering Congress and Exposition
Authors Abstract
Content
At the present time, it is generally conceded that testing for the evaluation of fatigue performance of materials subjected to variable loading in service, must contain variable loading as well. Single-level fatigue testing just will not provide an accurate answer.
Two methods of fatigue testing using variable amplitude have been advocated in the literature. The earlier method, developed by Gassner, involves the stratification of the service load spectrum into eight levels, from the maximum load to the minimum. The number of cycles at each level is developed from the load spectrum. The loads are then applied in a stepwise ascending-descending manner beginning with a mid-level.
The second method involves the use of a clipped random process, whose intensity (RMS) is varied throughout the test in a random stepwise manner, such that the final accumulation of loads is asymptotic to the desired load spectrum.
These two methods are examined in detail in this paper. A test program, involving automotive stub axles was developed, in which as many factors as possible were kept common to both types of tests. It is hoped that the results are a fair assessment of the two methods.
Meta TagsDetails
DOI
https://doi.org/10.4271/690050
Pages
18
Citation
Swanson, S., "Evaluating Component Fatigue Performance Under Programmed Random, and Programmed Constant Amplitude Loading," SAE Technical Paper 690050, 1969, https://doi.org/10.4271/690050.
Additional Details
Publisher
Published
Feb 1, 1969
Product Code
690050
Content Type
Technical Paper
Language
English