Investigation of cracking in small punch test for semi-brittle materials

The Gurson-Tvergaard-Needleman damage model is implemented in Small Punch (SP) Finite element model with the purpose of evaluating the influence of crack initialization and propagation on the SP force-displacement (F-v) curves and the maximum force, Fm, which is used for estimating the Rm. Five materials, significantly different in Rm and ductility are investigated. Numerical calculations are performed and compared to the the experimental measurements to evaluate the accuracy of the model. It is shown that the model is capable of capturing crack initialization in the semi-brittle 15-15Ti46CW and 15-15Ti24CW, both in terms of the number of cracks and their positions. For these two materials and the more ductile P92 and P92, the simulations indicate signifficant impact of damage on the F-v curves in the vicinity of the maximal force, Fm. This can signifficantly influuence the estimation of Rm from the Fm and vm points. However, the model tends to predict the crack initialization at a larger displacement compared to the experiments.

SIMONOVSKI Igor;  HOLMSTROM Bjorn;  BARALDI Daniele;  DELVILLE Remi; 

2020-06-30

ELSEVIER SCIENCE BV

JRC119264

0167-8442 (online),   

https://publications.jrc.ec.europa.eu/repository/handle/JRC119264,   

10.1016/j.tafmec.2020.102646 (online),