Become an expert in R — Interactive courses, Cheat Sheets, certificates and more!
Get Started for Free

Fatigue

Cracks caused by metal fatigue


Description

The Fatigue data frame has 262 rows and 3 columns.

Format

This data frame contains the following columns:

Path

an ordered factor with levels 1 < 2 < 3 < 4 < 5 < 6 < 7 < 8 < 9 < 10 < 11 < 12 < 13 < 14 < 15 < 16 < 17 < 18 < 19 < 20 < 21 giving the test path (or test unit) number. The order is in terms of increasing failure time or decreasing terminal crack length.

cycles

number of test cycles at which the measurement is made (millions of cycles).

relLength

relative crack length (dimensionless).

Details

These data are given in Lu and Meeker (1993) where they state “We obtained the data in Table 1 visually from figure 4.5.2 on page 242 of Bogdanoff and Kozin (1985).” The data represent the growth of cracks in metal for 21 test units. An initial notch of length 0.90 inches was made on each unit which then was subjected to several thousand test cycles. After every 10,000 test cycles the crack length was measured. Testing was stopped if the crack length exceeded 1.60 inches, defined as a failure, or at 120,000 cycles.

Source

Lu, C. Joséph , and Meeker, William Q. (1993), Using degradation measures to estimate a time-to-failure distribution, Technometrics, 35, 161-174


nlme

Linear and Nonlinear Mixed Effects Models

v3.1-152
GPL (>= 2) | file LICENCE
Authors
José Pinheiro [aut] (S version), Douglas Bates [aut] (up to 2007), Saikat DebRoy [ctb] (up to 2002), Deepayan Sarkar [ctb] (up to 2005), EISPACK authors [ctb] (src/rs.f), Siem Heisterkamp [ctb] (Author fixed sigma), Bert Van Willigen [ctb] (Programmer fixed sigma), Johannes Ranke [ctb] (varConstProp()), R-core [aut, cre]
Initial release
2021-02-03

We don't support your browser anymore

Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.