Crack paths in smooth and precracked specimens subjected to multiaxial cyclic stressing
Journal Title: Frattura ed Integrità Strutturale - Year 2015, Vol 9, Issue 34
Abstract
The understanding of shear-mode crack growth mechanisms and crack branching phenomena is of great interest for a variety of practical engineering situations. Despite this fact, relatively little research is available regarding these topics. Of the studies that have been performed, few provide a means of quantifying such effects and most consider crack growth starting from a precrack. The current study is aimed at trying to fill some of the research voids in these areas by investigating the effects of microcrack coalescence, loading level, and superimposed normal stresses on the mode II crack behavior of naturally initiated fatigue cracks. Based on the experimental results and subsequent analyses, it was determined that microcrack networks and coalescence have little to no effect on the experimentally observed crack paths regardless of the applied loading level. Instead, the preferred crack growth mode is shown to have a dependence on the applied shear stress magnitude and stress normal to the crack plane, indicating a significant role of fiction and roughness induced crack closure effects in the crack growth process. A simple model is then proposed to quantify these effects based on the idea that crack face interaction reduces the effective mode II SIF by allowing a portion of the nominally applied loading to be transferred through a crack. The model agrees qualitatively with the experimentally observed trends for pure torsion loading and predicts crack branching lengths within a factor of 2 for all loadings considered.
Authors and Affiliations
Nicholas Gates, Ali Fatemi
Keywords
Related Articles
- EP ID EP117492
- DOI 10.3221/IGF-ESIS.34.03
- Views 56
- Downloads 0
Crack initiation at V-notch tip subjected to in-plane mixed mode loading: An application of the fictitious notch rounding concept
The fictitious notch rounding concept is applied for the first time to V-notches with root hole subjected to in-plane mixed mode loading. Out-of-bisector crack propagation is taken into account. The fictitious no...
An efficient Bouc & Wen approach for seismic analysisof masonry tower
The assessment of existing masonry towers under exceptional loads, such as earthquake loads,requires reliable, expedite and efficient methods of analysis. These approaches should take into account boththe randomnes...
L’infragilimento da idrogeno. Un caso di studio in una barra di comandi di un velivolo dell’aviazione generale.
La degradazione delle caratteristiche meccaniche di un materiale di impiego aeronautico ha pesanti ricadute sulla sicurezza del volo. Tale degradazione si può manifestare sia per l’effetto combinato tra l’ambiente...
Analysis of cracking of low-alloy copper stretched at elevated temperature
This paper presents both mechanical and structural aspects of micro-cracking of CuNi2Si copper alloy in CNCS grade revealed during the static tensile test in the temperature range between 20ºC and 800ºC. The...
Fatigue methodology for life predictions for the wheel-rail contact area in large offshore turret bearings
The present report presents a fatigue life prediction method for large roller bearings applied in the turret turn table for large loading buoy units. The contact points between wheel and rail in these bearings are...