Assessment of fatigue striation counting accuracy using high resolution scanning electron microscope

Hershko, Emmanuel; Mandelker, Nir; Gheorghiu, George; Sheinkopf, H.; Cohen, Ignacio Sánchez; Levy, Ofer

doi:10.1016/j.engfailanal.2007.01.005

Cited by 38 publications

(13 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the number of field incidents which presented visible striations was too small to allow for the striation count with a certain confidence interval. Ultimately, the HCF striations were too fine to accurately resolve, and did not follow a decay with depth as do LCF striations, supporting conclusions of Hershko et al [66] and Cherolis [67] .…”

Section: Fractographic Investigations Of Fractured Compressor Bladessupporting

confidence: 62%

On the Fatigue and Fracture of Bladed and Integrally Bladed Rotors of Aircraft Engine Compressors

Mangardich¹

2021

Preprint

View full text Add to dashboard Cite

The fatigue and fracture for bladed and integrally bladed rotors (IBR) of aircraft engine compressors has been studied. For IBRs, a new distinct finite element technique was developed to model crack propagation under combined low cycle and high cycle fatigue loading. The crack trajectory, aspect ratio, and shape resulting from the method agreed very well with airfoils which fractured in service. The technique can be extended on other compressor disk applications. For bladed rotors limited by fretting fatigue, a unique fracture mechanics based methodology was developed for obtaining an evolved coefficient of friction (COF) resulting from fretting motion between the fan blade and hub. The predicted nucleation location, nucleation life, crack trajectory, shape and propagation life agreed well with the fractured components. The study confirms that the fretting-specific modified Smith-Watson-Topper (SWT) parameter more accurately predicts the nucleation location and life of the crack compared to the plain fatigue SWT parameter.

show abstract

Section: Fractographic Investigations Of Fractured Compressor Bladessupporting

confidence: 62%

On the Fatigue and Fracture of Bladed and Integrally Bladed Rotors of Aircraft Engine Compressors

Mangardich¹

2021

Preprint

View full text Add to dashboard Cite

show abstract

“…The fatigue striation spacing is an indicator of the local fatigue crack propagation rate. Therefore, for quantitative analysis, the fatigue striations per unit length were measured, and then the crack growth rates were calculated [ 36 ]. The results of the average number of fatigue striations per micron in the internal fisheye area and the crack growth rate are shown in Table 5 .…”

Section: Discussionmentioning

confidence: 99%

Effects of the Ultrasonic Assisted Surface Rolling Process on the Fatigue Crack Initiation Position Distribution and Fatigue Life of 51CrV4 Spring Steel

et al. 2021

View full text Add to dashboard Cite

In this paper, the effects of the fatigue crack initiation position (FCIP) on fatigue life are discussed. Different modified gradient fields (MGFs) are prepared on the surface of 51CrV4 spring steel components by an ultrasonic assisted surface rolling process (USRP). Subsequently, the fatigue behaviour of steels with different FCIPs is systematically studied. The results show that the fatigue life of steels first exhibits an increasing tendency and then a decreasing tendency with increasing distance between an FCIP and the surface. When an FCIP shifts from the surface of the sample to the interior, the fatigue crack initiation resistance on the interior is greater than that on the surface, which leads to an increase in fatigue life. However, when the FCIP further shifts towards the centre of the specimen, the stress triaxiality experienced by the fatigue source gradually increases, which results in a peak in the curve of FCIP versus fatigue life. The magnitude of this peak fatigue life is related to the change in the stress triaxiality. Moreover, according to focused ion beam-high-resolution transmission electron microscopy (FIB-HRTEM) microstructural analysis near FCIPs, under a higher stress triaxiality, the crack tip area is subject to greater stress constraints, making the multiplication and movement of dislocations in this area more difficult, resulting in the decrease in movable dislocation density. This decrease in dislocation density leads to an increase in the stress concentration and accelerates the crack growth rate, decreasing the fatigue life. Therefore, the significant change in fatigue life is controlled by the MGF and stress triaxiality.

show abstract

“…The da/dN values were calculated from the distances between the fatigue striations on the fracture surface by the use of SEM micrographs. For this purpose, after estimating the crack initial origin, the striation widths were calculated along two straight lines from the initiation zone to the final fracture [8][9][10]. By moving away from the origin, it was tried to find striations at different spacings from the initiation zone.…”

Section: Stress Analysis and Discussionmentioning

confidence: 99%

A failure analysis study on the fractured connecting bolts of a filter press

Molaei

Alizadeh

Attarian

et al. 2015

Case Studies in Engineering Failure Analysis

View full text Add to dashboard Cite

Assessment of fatigue striation counting accuracy using high resolution scanning electron microscope

Cited by 38 publications

References 3 publications

On the Fatigue and Fracture of Bladed and Integrally Bladed Rotors of Aircraft Engine Compressors

On the Fatigue and Fracture of Bladed and Integrally Bladed Rotors of Aircraft Engine Compressors

Effects of the Ultrasonic Assisted Surface Rolling Process on the Fatigue Crack Initiation Position Distribution and Fatigue Life of 51CrV4 Spring Steel

A failure analysis study on the fractured connecting bolts of a filter press

Contact Info

Product

Resources

About