crack: Fatigue Crack Growth Degradation Dataset

In IGPFrailty: Inverse Gaussian Process Degradation Models with Frailty

Fatigue Crack Growth Degradation Dataset

Description

Experimental fatigue crack length measurements on 21 alloy specimens subjected to cyclic stress testing up to 0.12 million cycles (120 thousand cycles).

Usage

crack

Format

A data frame with 262 rows and 6 variables:

specimen

Integer specimen identifier (1 to 21).

megacycles

Inspection time in millions of cycles (0.00 to 0.12).

cycles

Inspection time in cycles (0 to 120,000).

t

Inspection time in thousands of cycles (0 to 120).

inches

Crack length measurement in inches (initial crack 0.90 inches, failure at 1.60 inches).

deg

Transformed cumulative degradation D^*(t) = \log(D(t) / 0.90), with failure threshold \rho = 0.5754.

Source

Lu, C. J., & Meeker, W. Q. (1993). Using degradation measures to estimate a time-to-failure distribution. Technometrics, 35(2), 161-174. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1080/00401706.1993.10485038")}.

Morita, L. H. M., Tomazella, V. L. D., Balakrishnan, N., Ramos, P. L., Ferreira, P. H., & Louzada, F. (2021). Inverse Gaussian process model with frailty term in reliability analysis. Quality and Reliability Engineering International, 37(2), 763-784. \Sexpr[results=rd]{tools:::Rd_expr_doi("10.1002/qre.2762")}.

Examples

data(crack)
head(crack)

IGPFrailty documentation built on Aug. 25, 2026, 9:08 a.m.