Nondestructive Evaluation of Metal Fatigue.
Abstract
The magnetic field perturbation method was further developed as a means of determining the fracture criticality of fatigue cracks in ferromagnetic steels; supplementary techniques used included ultrasonic surface waves and ferromagnetic Barkhausen noise analysis. Rod-type specimens of AISI 4340 steel were used. An analytical model relating the crack opening displacement (COD), crack depth and applied tensile stress was developed and found to agree well with experimental measurements of these parameters. The magnetic perturbation signal amplitude was found to quantitatively correlate with the COD. It was found possible to obtain the crack length from magnetic perturbation signals obtained from multiple parallel scans across the crack interface. Preliminary investigations were carried out with the ferromagnetic Barkhausen noise method to assess its potential as a means of characterizing the residual stress field in the vicinity of a fatigue crack, with promising results.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1975
- Accession Number
- ADA013133
Entities
People
- F. N. Kusenberger
- G. A. Matzkanin
- Joshua R. Barton
- Philip H. Francis
Organizations
- Southwest Research Institute