Title
Incremental Driver
Description
Incremental Driver is a single element code developed by Andrzej Niemunis (2007, 2014, 2023) for running element tests using constitutive models implemented in umat format. Virtually any element test may be simulated using a general test specification procedure described in the software manual, standard tests are pre-defined.
License & Website
Available Constitutive Models
Clay hypoplasticity is an advanced incrementally non-linear constitutive model based on critical state soil mechanics developed specifically for simulation of fine-grained materials.
SANISAND is an advanced elasto-plastic model based on a concept of rotational hardening incorporating the effects of fabric-dilatancy.
Sand hypoplastic model is an advanced incrementally non-linear constitutive model for sand, an outcome of an extensive research at Karlsruhe University in 1990's.
Barodesy is a constitutive model for granular media and does not use standard notations of elasto-plasticity, e.g. yield function, flow rule or plastic potential.
A high-cycle explicit model for the accumulation of strain in sand due to small cyclic loading. The dependence of the accumulation rate on stress, void ratio, cyclic history and the type of loading is considered. In particular, the ovality and the polarization of the strain path during a cycle are taken into account.
Various extensions of the original concept of intergranular strain (IS) according to Niemunis and Herle (1997), to account for small strain effects in constitutive models, have developed in recent years.
This page (which is currently under construction) is intended to provide an overview of existing intergranular strain extensions combined with corresponding implementations.
Related Downloads
Download package of a Incremental Driver single element program by Niemunis (2007, 2014) for running element tests using constitutive models implemented in umat format.
Implementation (umat.for) of a model published in Mugele, L., Stutz, H. H. and Mašín, D. (2024). Generalized intergranular strain concept and its application to hypoplastic models. Computers and Geotechnics 173, September 2024, 106480.
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Related SoilModels Forum Posts
A PhD-level course on hypoplastic constitutive modelling intended for both academia and practitioners.
SoilModels News – Barodesy, Incremental Driver update, post views count and ExCalibre input files
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Number of interesting news at SoilModels from past week: New Barodesy constitutive model, umat with source code and Plaxis DLL. Thanks to the researchers from the University of Innsbruck (Barbara […]
I have tried to compile IncrementalDriver to use it with sanisand model. I found it impossible to compile due to absence of the module unsymmetric_module called in the first line of the main program. The module unsymmetric_module is also called in the subroutines get_increment and rotsig. Can anyone help?
Regards,
Krzysztof
Hi Krysztof, I do not know myself, but will try to forward your question to Andrzej Niemunis, Incremental Driver author. Maybe also someone else helps. In the meanwhile, you can run sanisand umat in soilmodels.com/triax, but you would need Linux to link umat. Regards David
Thank you for the quick reply!
There is one more problem. When I eliminated the calls of the module unsymmetric_module by putting them into comments (! at the beginning of the line) the compiler revealed that some other subroutines are missing, i.e. map2T, map2stress, map2d, map2stran. Probably these subroutines were included in the same file IncremetalDriver.f in its previous version, but in the updated version of IncrementalDriver they have been moved to external file(s).
I will try to compile sanisand umat in triax under Linux anyway. Thank you for the hint. Regards, Krzysztof
Dear Krysztof, if you like I can also give you some hints how to compile it under windows, with the same commands.
Hi Henning, it would be great if you could provide the explanation. I will then put that info directly into the download package description.
Dear Henning, I warmly welcome your help. The problem is that triax is coded in C++ which I do not use. I use Fortran, that is why IncrementalDriver was my first choice. Only very recently I installed the free compiler and IDE Dev-C++ under Windows. If this fact does not discourage you, I am open to any help.
Krysztof, I now uploaded updated version of Incremental driver, provided by Andrzej Niemunis in 2016. Please try this, maybe it resolves your problems. If not, Andrzej replied that he will check your problem.
David, I have compiled incrementalDriver. So far, so good. Thx
Hi David and Krysztof,
I will do in the next days. Basically, you can install cygwin64 and must add it to the path variable in windows. As I remember this should be enough. The problem is that I have done it a long time ago. I have to repeat it on a computer without the installation.
Hi Hennig, thanks for help. As a matter of fact, the version of Incremental Driver was older, which was probably the cause of the troubles of Krzystof. I have uploaded the most recent version (2016) yesterday and it seems Krzystof could compile it. I think you can let it be for now, maybe do it later if someone else is in trouble. Regards David
Henning, David is right. I will try using incrementalDriver and see what happens. Anyway, I appreciate your help! Maybe I’ii take advantage of it in the future.
David, I appreciate your help too!
Krzysztof, still some news. Andrzej Nimeunis just provided 2017 version of Incremental Driver, which can now be downloaded, so you can try.
Ok, please don´t hesitate if you want to try to compile triax+Umat under windows.
Hi Henning, but that would help. If you can please prepare the description, I will put it into installation instructions of Triax.
IncrementalDriver can be compiled provided that the line 531 ends by 72nd column. This is the only bug I have noticed.
Hi Krzysztof, thanks for pointing this out, Andrzej Niemunis confirmed the error and submitted corrected version, which is now in the download section.
Hello all,
I have a very simple question regarding incremental driver. We are using it for drained triaxial compression using one of the umat files we developed. The issue with umat is that only takes incremental strain as an input and then calculates incremental stress and update the stress state as well as other state parameters. This obviously causes an issue with triaxial tests where you need to specify a stress boundary condition in radial direction. As we understand, Incremental Driver resolves this issue by iterating the strain increments to reach to the specified stress condition at radial boundaries. However, we are having massive drift in radial stress even if we specify maximum number of iterations to a big number (maxiter=100 for instance). I wonder if anyone else is having a similar issue as we experience and how they resolve it. Looking through the Fortran code, we could not find any sort of convergence algorithm that is used; the code simply keeps iterating until maxiter is reached. Maybe we are looking in a wrong place? Your help would be much appreciated.
Regards,
Ulas