Modeling of fatigue crack initiation in wire-bonds using a novel approach of strain gradient theory

Author(s)
Martin Lederer, Golta Khatibi, Dominik Thuiner, Herbert Danninger
Abstract

The fatigue life of wire-bonds was measured with use of a 20 kHz ultrasonic testing system. Thereafter, the experiments were interpreted by Finite Element Analysis. First, simulations were performed according to classical continuum mechanics. They predicted stress concentrations at the location where crack initiation was found experimentally. However, the stress concentrations showed the characteristics of stress singularities even for loading cases corresponding to the regime of very high cycle fatigue, i.e. fairly moderate loads. In subsequent simulations, the singularities of stress concentrations could be removed on the basis of a newly developed version of strain gradient elasticity, resulting in predictions that agreed well with experimental results.

Organisation(s)
Physics of Nanostructured Materials
External organisation(s)
Technische Universität Wien
Journal
Key Engineering Materials
Volume
592-593
Pages
246-249
No. of pages
4
ISSN
1013-9826
DOI
https://doi.org/10.4028/www.scientific.net/KEM.592-593.246
Publication date
2014
Peer reviewed
Yes
Austrian Fields of Science 2012
102009 Computer simulation, 103018 Materials physics, 201108 Fracture mechanics
Portal url
https://ucrisportal.univie.ac.at/en/publications/modeling-of-fatigue-crack-initiation-in-wirebonds-using-a-novel-approach-of-strain-gradient-theory(868fe7ad-4872-4412-bd13-53d7b3737931).html