A model for roughness-induced fatigue crack closure

Journal Article · Wed Jul 01 04:00:00 EDT 1998 · Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science

DOI:https://doi.org/10.1007/s11661-998-0018-0· OSTI ID:634567

Wang, S H; Mueller, C; Exner, H E ^[1]

---

1. Darmstadt Univ. of Technology (Germany)

A model for predicting the crack closing stress intensity factor for roughness-induced closure of fatigue cracks is developed based on a two-dimensional approach considering crack opening and closure of an idealized crack path. The model highlights the contribution of irreversible cyclic planar slip at the crack tip, and is extended to real cases describing roughness-induced crack closure as a function of fracture surface roughness parameters at low {Delta}K levels where planar slip prevails. The resulting equation indicates that roughness-induced crack closure depends on the maximum stress intensity factor, the standard deviation of heights as well as the standard deviation of angles of the crack profile elements, and the yield stress of the material. Comparison between the prediction of the model and experimental data of K{sub cl} for lamellar microstructures of Ti-2.5Cu as well as TIMETAL 1100 shows good agreement.

• Sponsoring Organization: USDOE
• OSTI ID: 634567
• Journal Information: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 7 Vol. 29; ISSN MMTAEB; ISSN 1073-5623
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CORRELATIONS
CRACKS
FATIGUE
MATHEMATICAL MODELS
PREDICTION EQUATIONS
ROUGHNESS
STRESS INTENSITY FACTORS
TITANIUM ALLOYS