Overall Budget: ca € 120’000
Sectoral Group: EuroHM
Contractors: RWTH Aachen University (Germany), NPL (UK), UPC (Spain

SIMU-CRACK is a research project in which simulation and experimental activities are effectively combined to study, document, analyse, understand and predict the fatigue crack growth (FCG) behaviour of Hardmetals. Four SIMU-CRACK stages have been completed up to now, and last one focused on studying the influence of carbon content and local material properties on fatigue behavior of cemented carbides.

From the experimental perspective, it was found that:

(1) FCG mechanisms in low carbon and high carbon specimens are very similar; and

(2) high-carbon samples exhibit lower and more dispersed fatigue lives than low-carbon ones.

Meanwhile, simulation models were able to predict FCG rate ratios between low- and high- carbon specimens in accordance with the experimental results. However, the numerical and experimental studies during SIMU-CRACK IV have also revealed the necessity for in-depth knowledge about the influence of carbon content on fatigue. Particularly, the scatter in experimentally results could not be reproduced by simulation model.

Proposed experimental and numerical work in SIMU-CRACK V aims to close the present knowledge gaps by a comprehensive study of hardmetals reliability. It includes a novel experimental approach addressing statistically analysis (Weibull distribution) of residual strength assessment in previously damaged samples. In this regard, introduction of distinct damage levels will be attempted by cyclic load testing of pristine/unnotched samples up to different fractions of the expected fatigue life. Numerical model will then be validated using the experimentally derived Weibull parameters.

In SIMU-CRACK V, the interaction between simulation and experiment is even closer than in previous stages, i.e. simulation outcomes will be used to predict the experimental results which can help to reduce the number of tests. Main anticipated improvements on numerical side are the constitutive and damage models of binder phase in hardmetals with varying carbon content. The planned work is distributed among six work packages (WPs).