I am happy to announce that our pre-print paper, “Multi-objective analysis of the Sand Hypoplasticity model calibration”, is available on researchgate (https://www.researchgate.net/publication/369199567_Multi-objective_analysis_of_the_Sand_Hypoplasticity_model_calibration) and Axive (https://doi.org/10.48550/arXiv.2303.07234). In this work, we study […]
Hello all, I’m using the SANISAND UMAT I downloaded here for my research, the problem I found is it gives me wrong results in ABAQUS and INCREMENTAL DRIVER for element […]
Prague Geotechnical Days 2023 (22nd – 23rd of May) with Prague Geotechnical Lecture by prof. Yannis Dafalias
||Event Announcements|1 |
The 29th Prague Geotechnical Days international conference focused on issue of Cyclic Loading of Geotechnical Structures will be held on May 22–23, 2023 Registration: free for students, 80 EUR otherwise […]
What is an appropriate damping model for dynamic liquefaction analysis of tailings storage facility in FLAC?
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Has anyone had success simulating earthquake loading / dynamic liquefaction in a full-scale, plane-strain model of a TSF in FLAC2D/FLAC3D? The topic of damping is complex and the choice of […]
Hi, I have a question regarding local, material-level convergence tolerances in FE software, particularly Abaqus and Plaxis. I have experience using Abaqus but not much familiar with Plaxis. As shown […]
Hi all, We are happy to announce that the Excalibre team received support from the research grant GACR 22-12178S to further develop the calibration software, which is freely available at […]
Hello, I am simulating soil and pile using Sanisand on Abaqus. I have problems with the analysis because of the value of the parameter 18. When I use small values, […]
Hello.. I am using SaniSand constitutive model, for the simulation of the behavior of onshore wind turbine using plaxis 3d. The dll file published in the website request the determination […]
The GA-cal software for the automatic calibration of soil constitutive laws
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I am happy to announce that our pre-print paper, “The GA-cal software for the automatic calibration of soil constitutive laws: a tutorial and a user manual”, is available on researchgate […]
Hello.. I am testing SaniSand constitutive model as published by Mr. Masin at this site. The Abaqus is V21 and the visual studio 2017 with OneAPI compiler, the Abaqus verification […]
Few more Question on calculating lateral displacement of pile using hypoplastic clay model
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Dear Professor David, Thank you very much for your previous clarification. its really helps. In continuation to my previous , there are few more question, i want your kindself to […]
Hello, I am writting to ask how to get the elastic modulus or undrained strength of the soil in the simulation model by using hypoplastic model in clay? Is there […]
Problem in calculating Lateral displacement of the pile using Hypoplastic clay model
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Hy Professor David, I am trying to verify the result of one of your paper by the title ‘Cyclic lateral response and failure mechanisms of semi-rigid pile in soft clay: […]
Special issue of Computers and Structures “Numerical simulation of multi‐physics phenomena in geotechnical structures”
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https://www.sciencedirect.com/journal/computers-and-structures/about/forthcoming-special-issues Numerical simulation of multi‐physics phenomena in geotechnical structures Complete and thorough analysis of geotechnical structures, requires various complex materials models with internal structures, which cannot be described by the […]
Post-doctorate position at Nantes University (France) in geotechnical analysis of mutualized anchors
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Dear colleagues, France Energies Marines is conducting, together with other partners (Nantes Université, EDF, WPD, TotalEnergies, Technip Energies, Université Grenoble Alpes, Innosea, Eolfi, Saipem, Université Gustave Eiffel), the MUTANC project. […]
Hi, I’m facing a problem with my model. I’m trying to simulate a helical pile in soil. When I create the job, my job doesn’t make any increment and the […]
Hi altruists, Hope all of you are doing well. I am looking for literature on the NorSand model, which considers the drained cyclic triaxial testing behavior. I have found a […]
Post-doc position at Charles University in the field of THM analysis of unsaturated and heated soil cyclic loading
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International Postdoctoral Fellowship – Earth and Environmental Sciences Topic: In many geotechnical problems either saturated or unsaturated soils are subjected to a cyclic coupled thermo-hydro-mechanical (THM) loading. A prominent example […]
Hello all, I am using the clay hypoplsticity model in Abaqus. As shown in the picture, I have to construct the stiffness desegregation curve to calibrate the R value. Can […]
Dear Prof Stutz and Prof Mašín, Is FRIC code for clay hypoplasticity available? If yes, could you please provide me with the link to download FRIC? Thank you Haran
Hello everyone, Is it possible to use pore fluid- stress element in abaqus standard when soil is modeled using SANISAND constitutive model ? (UMAT)
Hello Everyone, I am using the UMAT code for clay hypoplasticity provided by Prof. Masin — https://soilmodels.com/download/plaxis-umat-hypoplas-zip/ I made a test model in Abaqus2020 and applied the umat code (umat_hcea.for). […]
Prague Geotechnical Days 2022 with Prague Geotechnical Lecture by prof. Cino Viggiani
||Event Announcements|0 |
Everyone is cordially invited to attend Prague Geotechnical Days 2022, scheduled for May 23-24, which include Prague Geotechnical Lecture by prof. Cino Viggiani entitled “Recent Developments in Laboratory Testing of […]
Hello, This Abou Alhaija Majd, Ph.D. student at Technical University of Civil Engineering Bucharest, i am looking for Micropiles load test data to be used for calibration in my study, […]
DIANA 10.5 was released in 2021. It features many powerful capabilities to model soil-structure interection. See more in https://dianafea.com/2021-DIANA10-5-Release
I’m interested in using the model for simulating excavations in clay, where the small strain modulus is important, and the analysis has to be transient consolidation. It would be helpful […]
Hi everyone, i have combined both Hypoplastic sand and clay umats in one umat ( to use for example in the case of multilayered soil medium made of clay and […]
Hello Everyone, I am trying to implement an unsaturated soil model (BBM or similar) in ABAQUS using UMAT. We want to assign a pore-pressure boundary condition for simulating the drying […]
I have a UMAT of Mohr Coulomb with no hardening, where i have to define SSE (specific strain energy) and SPD (specific plastic dissipation). Any idea?
Hi all, Details of Excalibre software (https://soilmodels.com/excalibre) functionality and calibration procedure have been published in two papers, which are now available online at the webpages of publisher (https://link.springer.com/article/10.1007%2Fs11440-021-01441-0 and https://link.springer.com/article/10.1007%2Fs11440-021-01435-y). […]
Dear all, I want to implement a new user element using the UEL subroutine. To simulate dynamic cases, one has to define the mass, damping and stiffness matrix then build […]
Three PhD positions in soil mechanics at Charles University, Czech Republic
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The Soil Mechanics group led by David Mašín at Charles University, Prague, Czech Republic, is seeking three motivated PhD students with experience in modelling and/or experiments to work on the […]
Hi all, Can anyone give a clarification on the material property (parameter 22) in the hypopplasticity umat for clay on Abaqus. My understanding is that these parameters are defined as […]
Hi everyone, i want to carry out some transient dynamic analysis. as far as I know, dynamic steps in abaqus does not allow for pore pressure build-up and dissipation, and […]
Modelling TX monotonic compressive test with ABAQUS and SANISAND – not working
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I am trying to reproduce a TX monotonic, compressive test on a sand by using a 1-element, axisymmetric ABAQUS FE model, assigned to a SANISAND material. For this purpose, I […]
Dear all I have FEM analysis results for vibration foundation response that rested either on saturated salt-encrusted flat soil (case-1) or on finite cemented sand overlie saturated salt-encrusted flat soil […]
Hello All, I am getting started with implementing UMAT for soil model in ABAQUS. I am planning to use Hypoplastic clay constitutive soil model to simulate the triaxial tests. I […]
Dear all, Thanks for hypoplasticity sand UMAT provided by Prof. Masin. During studying hypo sand UMAT, I am encountered with a question about consistent tangent stiffness calculation. subroutine ”perturbate_h“ seems […]
Dear forumers: Thanks to hypoplasticity sand UMAT provided by Prof. Masin — https://soilmodels.com/download/plaxis-umat-hypoplas-zip/. But during studying above sand UMAT, I found that the stress order may be incorrect. Because stress […]
ALERT doctoral school on constitutive modelling – hands on session triax input files
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ALERT doctoral school on constitutive modelling is happening right now. The school lecture notes are available at the website of ALERT geomaterials (http://alertgeomaterials.eu/publications/) Below you find triax input files for […]
Hi, I am using Hypoplasticity model with explicit asymptotic boundary surface proposed by Prof. Masin in 2014. In this model, parameter ‘nu’ controls initial stiffness in CU test. But when […]
Can SANISAND version given in soil model work well for cyclic simple shear test ?
Hi Admin, I have been using hypoplastic subroutine supplied by this website. It works well in ABQ6.14 and ABQ2017. However, recently I have to upgrade to ABQ2021 due to an […]
Hi everyone, i am modeling laterally loaded monopile using abaqus, My 3d model looks like this, only half of the model is simulated, symmetry boundary conditions is applied to the […]
Dear Altruists, I just wanted to learn the bounding surface plasticity theory with coding. Does anyone have any code (written in MATLAB) for the Bounding Surface Plasticity model? Could you […]
Non convergence problem in abaqus using hpoeca Clay Hypoplasticity in slope model
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hello everyone! based on the strength reduction method in clay hypoplasticity, firstly, I used two steps belong to the static_general, the first step is impose a gravity load, and not […]
Anyone has any reference to writing UMAT file for Poro linear elastic properties or what constitutive equations have to be solved to do the same. Any help would be appreciated […]
Hi everyone, i am trying to simulate DSS/cDSS test in drained/undrained conditions and I was wondering how the constraints matrices should be ? while it is easy to understand how […]
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Recent posts
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Postdoctoral position at COFS, UWA 28.7.2025
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Hypoplasticity clay in ABAQUS 23.7.2025
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Drucker-Prager Cap 29.5.2025
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Abaqus RITSS with hypoplastic 9.4.2025
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Fellin UMAT subroutine 2.4.2025
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Hypoplasticity clay for triaxial compression in abaqus 26.3.2025
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Abaqus RITSS methon for LDFE analysis with hypoplastic 17.3.2025
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Request for VUMAT Implementation of Mohr-Coulomb, Drucker-Prager, or Drucker-Prager Cap 28.2.2025
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Suggestions for an Advanced Constitutive Model in FEM-Based Dynamic Slope Stability Analysis 12.2.2025
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Hardening Soil or Hardening Soil-Small umat in Abaqus 2.1.2025
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hypoplastic interface 11.12.2024
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Triaxial Test Driver SANISAND 30.10.2024
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