Determination of deformation and failure properties of ductile materials by means of the small punch test


The experimental method of the small punch test is used to determine the material response under loading. The resulting load displacement curve is transferred to a neural network, which is trained using load displacement curves generated by finite element simulations of the small punch test and the correspond-ing material parameters. The simulated material behaviour of the specimen is based on the ductile elastic plastic damage theory of GURSON, TVERGAARD and NEEDLEMAN. During a training process the neural network generates an approximated function for the inverse problem relating the material parameters to the shape of the load displacement curve of the small punch test. This technique was tested for different materials (ductile steels). The identified parameters are verified by testing and simulating notched tensile specimens.


small punch test, neural network, damage, ductile fracture, finite elements


M. Abendroth, M. Kuna, Bestimmung von Verformungs- und Versagenseigenschaften duktiler Werkstoffe aus dem Small Punch Test, in DVM-Bericht 235, "Fortschritte in der Bruch- und Schädigungsmechanik", 261-270, 2003