SANISAND Abaqus UMAT and Plaxis implementations

Description: Abaqus UMAT and Plaxis implementations of SANISAND constitutive model by Dafalias and Manzari (2004).

Authors: Original implementation by M. Martinelli, C. Miriano and C. Tamagnini. Updated version of umat together with Plaxis interface programmed by D. Mašín. The updated version has been developed under the support of Zhejiang University, Hangzhou, China. Special thanks to Prof. Lizhong Wang and to a. Prof. Yi Hong for releasing the implementation to SoilModels users.


  • Dafalias, Y. F. and Manzari, M. T. (2004). Simple plasticity sand model accounting for fabric change effects. Journal of Engineering Mechanics, Volume 130, No. 6, 622-634.

Associated Software and Constitutive Models

  1. Win Mar Soe
    Win Mar Soe 10 months ago

    Hi, where can I read more details about sanisand model and what is the procedure to use in plaxis?

    • David Mašín Author
      David Mašín 10 months ago

      Hi, please re-download the package, now you will find pdf files with information you need. regards David

  2. Krzysztof Sternik
    Krzysztof Sternik 10 months ago

    Hi David, in the file umat-sanisand-readme.pdf it is mentioned that there are two ways of generation of model parameters and state variables: standard and expert. Both involve usage of the subroutine sdvini.f. This file is missing in the package. Could you help?

    • David Mašín Author
      David Mašín 10 months ago

      Hi Krzysztof, sdvini.f is no special, this is standard sdvini which you can get from Abaqus manual. In “standard” mode, you do not need it, you just must properly initialise number of state variables to 36 and set void ratio in Par19. In “expert” mode you need to understand what exactly each state variable means and initialise it accordingly in sdvini.f. But I do not think this is really needed, standard mode should be fine for most applications.

  3. Krzysztof Sternik
    Krzysztof Sternik 10 months ago

    Thank you!

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