Numerical Computation of Stress Intensity Factors in Ultrasonic Very-High-Cycle Fatigue Tests

S.H. Hasani Najafabadi; Stefano Zucca; D.S. Paolino; G. Chiandussi; Massimo Rossetto

doi:10.4028/www.scientific.net/KEM.754.218

Paper Titles

On the Modelling of Creep Fracture and Fatigue
p.202

Application of the Williams Expansion near a Bi-Material Interface
p.206

The Influence of Prefabricated Crack with Bias Angle on the Material’s Fracture Toughness
p.210

Shear Mode Stress Intensity Factors for Serrated Crack Fronts
p.214

Numerical Computation of Stress Intensity Factors in Ultrasonic Very-High-Cycle Fatigue Tests
p.218

Prediction of Elastic Properties of 3D4d Braided Composite Based on Hybrid Model
p.222

On the Scale-Transition in Multiscale Modeling of Ductile Damage
p.226

A Grain-Scale Model of Inter-Granular Stress Corrosion Cracking in Polycrystals
p.230

A Finite Element Based Analysis of Double Strap Bonded Joints with CFRP and Aluminium
p.237

HomeKey Engineering MaterialsKey Engineering Materials Vol. 754Numerical Computation of Stress Intensity Factors...

Numerical Computation of Stress Intensity Factors in Ultrasonic Very-High-Cycle Fatigue Tests

Abstract:

The correct computation of the Stress Intensity Factor (SIF) in ultrasonic Very-High-Cycle Fatigue (VHCF) loading conditions is a key issue when investigating the crack growth rate curve with pre-cracked specimens or when evaluating critical SIF values from fracture surfaces of failed specimens. Dynamic conditions related to the resonance of the vibrating specimen, contact nonlinearity between crack faces and stress singularity at the crack tip make the SIF computation difficult and cumbersome. Generally, numerical computation through Finite Element Models (FEMs) under non-linear dynamic conditions makes use of direct integration methods (implicit or explicit). However, in the high frequency regime of ultrasonic VHCF tests, the procedure may lead to an unacceptable computational time. In order to reduce the computational time, a hybrid procedure based on the Harmonic Balance Method (HBM) and on the Virtual Crack Closure Technique (VCCT) is originally presented and applied in this paper. The dynamic field parameters calculated with the HBM are used as input data for the computation of the SIF through the VCCT.