Publication detail

Modelling of Tortuous Crack Fronts in Shear Loading Mode

HORNÍKOVÁ, J. ŠANDERA, P.

Original Title

Modelling of Tortuous Crack Fronts in Shear Loading Mode

English Title

Modelling of Tortuous Crack Fronts in Shear Loading Mode

Type

abstract

Language

en

Original Abstract

The contribution is related to experiments on near-threshold fatigue cracks under shear modes II, III and II+III in bcc metals. Cylindrical bars with circumferential cracked notch were loaded by shear force. The notch is located in the cross-section where no bending moment is present and it is loaded in pure shear. In-plane pre-cracks with microtortuous crack front were created by compressive cyclic loading in mode I to obtain smooth fracture surfaces and, consequently, the effective values of crack driving force could be measured. The circumferential pre-crack front could be modelled as a serrated front of a linear roughness identical to the real one. As reported elsewhere, the fatigue crack in bcc metals loaded under shear modes II, III and II+III always grows by creation and coalescence of local tongues loaded in mode II. Therefore, the aim of the model was to calculate the local stress intensity factor k 2 as a driving force for fatigue crack initiation and growth along the whole serrated crack front.

English abstract

The contribution is related to experiments on near-threshold fatigue cracks under shear modes II, III and II+III in bcc metals. Cylindrical bars with circumferential cracked notch were loaded by shear force. The notch is located in the cross-section where no bending moment is present and it is loaded in pure shear. In-plane pre-cracks with microtortuous crack front were created by compressive cyclic loading in mode I to obtain smooth fracture surfaces and, consequently, the effective values of crack driving force could be measured. The circumferential pre-crack front could be modelled as a serrated front of a linear roughness identical to the real one. As reported elsewhere, the fatigue crack in bcc metals loaded under shear modes II, III and II+III always grows by creation and coalescence of local tongues loaded in mode II. Therefore, the aim of the model was to calculate the local stress intensity factor k 2 as a driving force for fatigue crack initiation and growth along the whole serrated crack front.

Keywords

shear modes, stress intensity factors, serrated crack front, fatigue crack growth, local mode II

Released

15.12.2017

Publisher

X-Academy

Location

Kuala Lumpur

Pages from

14

Pages to

15

Pages count

2