In this tutorial we can see how to create a model in ABAQUS/CAE with two yield criteria in UMAT.
The files used and created through the tutorial are accessible from this link.
To cite the implementation please refer to:
G. Molnár, G. Kermouche, E. Barthel, Plastic response of amorphous silicates, from atomistic simulations to experiments – A general constitutive relation, Mechanics of Materials, 114 pp. 1-8, 2017.
To cite the empirical material model please refer to:
G. Kermouche, E. Barthel, Mechanical modelling of indentation-induced densification in amorphous silica, Acta Materialia, 56 pp. 3222–3228, 2008.
More information on the material model developement can be found in:
G. Molnár, P. Ganster, A. Tanguy, E. Barthel, G. Kermouche, Densification dependent yield criteria for sodium silicate glasses – An atomistic simulation approach, Acta Materialia, 111 pp. 129-137, 2016.