Notched multiaxial fatigue of Al7050-T7451:on the need for an equivalent process zone size

Frattura ed Integrità Strutturale

J.L.A Ferreira¹  C.R.M da Silva¹  J.A. Araújo² 

[1] Federal Institute of Brasília, Brasília, Brazil;University of Brasília, Brazil;

关键词: Multiaxial fatigue;    Notched fatigue;    stress gradient;    Process zone;    Critical distance;    Al 7050-T7451;   

DOI  :  10.3221/IGF-ESIS.41.13

来源: DOAJ

【 摘 要 】

The aim of this work is to investigate stress gradient effects on the fatigue life estimation of notched Al 7050-T7451 specimens under combined torsion and push-pull loading conditions. Initially, simple push-pull and torsion fatigue tests in plain and notched specimens were independently conducted not only to obtain the material properties necessary to calibrate a standard multiaxial critical plane based model, but also to raise the critical distance versus life curves in tension (L  – Nf) and in torsion (L  – Nf). This latter step also required a Finite Element Elastic Stress Analysis of the notched specimens tested in the medium high-cycle fatigue regime. Then, proportional multiaxial fatigue tests were carried out using this same notched geometry. The combination of a multiaxial model with the theory of critical distance (TCD) was applied to estimate fatigue lives. For this aluminium alloy, neither the use of the L  – Nf nor L  – Nf combined with the predictive multiaxial model was able to estimate lives in an accurate way.

【 授权许可】

Unknown