PLAXIS V22 brings a major overhaul to the data structure of the material database and a more flexible and more robust way of handling project units. Due to these major changes, PLAXIS V22 will be installed alongside PLAXIS V21, instead of overwriting it. We have also taken precautions to prevent overwriting old projects: when opening, for example, V21 projects with PLAXIS V22, projects will automatically be saved as a converted copy with the _converted suffix. After the conversion, remeshing and recalculation are required. In this case, the original V21 project will remain unchanged. For V21 projects that only have their geometry and/or some material sets defined and are not calculated or meshed, these projects will be opened by V22 without converting to a saved copy. This means that in this case, once you save the project with V22, the original V21 project data is overwritten and saved with the new material database structure. It can then no longer be opened in V21.
For projects that include design approaches, during the conversion process from V21 to V22, all the defined design approaches and the material factors, as well as assignment of design approaches in the staged construction are converted, however the assignment of the material factor labels to the material models parameters are not carried over and therefore the user will need to re-assign these material factor labels.
Note that these converted projects are stored in the file format for PLAXIS V22, this means that earlier versions of PLAXIS will not be able to open the converted project files. To continue using V21, users can just open the original V21 project.
The major overhaul of the data structure of the material database brings the user better command line support, a side-panel warning and error system, and richer editing experience. When editing or inputting any of the material model parameters in the GUI, the PLAXIS software will now issue individual commands. This gives users traceability and leads to more easily understanding the command structure and objects names when considering automation using e.g. Python scripting.
In previous releases, PLAXIS would always warn or give errors about incorrect parameter ranges, or ratios between parameters when closing a material dataset and prevented exiting the dataset window until all errors were resolved. These warnings and errors are now part of the new side-panel warning and error system. By default, the warnings are collapsed and may be ignored by more advanced users. When expanding the side-panel warnings by clicking the "Show full feedback" link, it will show all the errors, warnings, and hints for the material dataset. Errors will gradually disappear as the user fills in the parameters, and these errors will only remain if there are true issues with the user's input.
This new side panel warning system also enables users to close a material set even if it has errors. The local and global material databases will give a visual clue that a material set is invalid. Of course, the pre-calculation checks done by PLAXIS will still prevent the user to calculate with invalid material sets.
For more information on some of these changes, see:
Creep is a common feature that occurs in rocks, for example, rock salt. Creep becomes an important factor in deformation and stress redistribution when considering the timescale of deep underground structures, like gas caverns or radioactive waste disposal sites that are designed to last hundreds of years. The pre-existing N2PC model based on Norton’s model for steady-state creep was introduced in 2018 and offered users capabilities to reproduce the basic features of creep in primarily rock salt, like temperature (2D only) and stress-dependent creep rates, 2 creep regimes, etc. This original model did not have a plastic failure mechanism, so based on user feedback we included such a failure mechanism to extend the model capabilities and uses. With the N2PC-MCT model released in the CONNECT Edition V22, we extend the original model with a Mohr-Coulomb and Tension cut-off failure surface (hence MCT). This extension allows the model to now not only perform accurate deformation analysis but also failure analysis, considering the time-dependent behavior of rocks at time scales spanning ten to hundreds of years.
For more info and background, see UDSM: N2PC-Salt and N2PC-MCT.
Rock is not a homogeneous material: the presence of faults, fractures, joints, and weakness planes influence the mechanical behaviour, often more than the properties of the rock material itself. In PLAXIS, constitutive models such as Jointed Rock and Hoek-Brown capture the behavior of small, smeared discontinuities, while the larger explicit discontinuities have traditionally been modelled through Interface elements. The new Discontinuity elements, introduced for PLAXIS 2D in Version 22, enable a simpler modelling workflow. Discontinuity elements simulate the localized effects of discontinuities in rock, including opening/closing and sliding. Discontinuities decouple the nodes in the mesh, enabling the relative displacement between the two faces of the opening, which are linked by a set of independent springs for which normal (kn) and shear (ks) stiffnesses can be specified. The mechanical properties of Discontinuities are defined through their own material sets, instead of depending on the surrounding material, which makes them easier to use and to port from project to project.
Read here on the comparison of the Jointed Rock model and these new Discontinuity elements: Modelling Rock mass using discrete discontinuities vs Jointed Rock
In today’s complex and multidisciplinary infrastructure projects there is a growing need to shorten the iterative process between geotechnical and structural analysis teams and re-use readily available model data, rather than rely on the exchange of some linear and uncoupled spring values between these teams.
With Soil-structure interaction analysis using super-elements, PLAXIS can smoothly connect the numerous structural analysis load cases with the geotechnical analysis model at the soil-structure interface.
The initial structural analysis package that PLAXIS can interoperate with in this way is RAM Elements. From the RAM Elements analysis, special files can be generated from the run load cases, which are subsequently imported by the user into PLAXIS 3D as super elements. Once the super elements are imported the user can select these in the Model Explorer and create "structural models" out of them. Users will need to ensure the geotechnical model contains the structure's imprint (i.e. the structure's outer confines) to create the correct interface (size and location) between the soil and the structure, so that the super element is applied correctly. A created "structural model" is then activated by the user in a phase in the staged construction mode, to include the structure's contribution at the soil-structure interface in the calculation. Once the calculation is finished, each phase with an active "structural model" will generate a results file with more accurate or realistic reaction forces and displacements at the soil-structure interface, based on the soil's true non-linear response. The files and values therein can be used in RAM Elements as input for subsequent structural analysis.
The switch to full parametric geometry back in PLAXIS 3D 2016, allowed users to deal with progressively more complex geometry and a more optimized, accurate mesh representation of the model geometry. The switch also meant that the CAD import in PLAXIS 3D no longer supported triangulated surfaces or triangulated volumes for the *.DXF, *.STP and *. STEP formats. Triangulated topographic surfaces had to be converted into NURBS-surfaces by the user, usually with an intermediate step in CAD software, before importing them into PLAXIS 3D. Such a surface would lose its details depending on the degree of smoothing applied by users during conversion to a NURBS-surface. For sub-surface topography the smoothing might be acceptable and could even improve the analysis by smoothing out unnecessary details. For other cases, for example surfaces that have steep inclines like open pit mine geometries, this might not be desirable.
In Version 22, PLAXIS 3D directly deals with triangulated surface and sub-surface topography again, through the introduction of *.OBJ and *.STL import. The intermediate conversion step is eliminated which makes it easier for users to import triangulated surfaces coming from applications like MicroStation, PLAXIS Designer, or Leapfrog, while at the same time retaining the original details of the surface.
Once triangulated surfaces have been imported, they mesh in the same way as every other surface in PLAXIS considering manual or automatic refining and coarsening, while retaining the surface’s original shape. Note that this functionality is currently available as a Technology Preview and cannot be guaranteed to work in all cases. One known limitation for this functionality is that geometry with very steep inclines over larger heights, will see some of those inclines to be smoothed out, like we could see with an open-pit mine geometry. In future versions of PLAXIS 3D, the robustness of this new functionality will be improved (including honoring steep inclines in the geometry), also considering feedback from users trying this functionality.
In addition to offering triangulated surface import, users will now also get more informative messages when trying to import files into PLAXIS, hinting at probable causes and solutions for these errors. Warnings could be partially failed import, difference in units between the importable and the project, geometry far from the origin etc. This is done with the introduction of side panel warnings and an import log in the import dialog window. By pressing the Show import log button, the user can inspect the details of the import action and pointers to the objects causing errors. The full log details will also be useful for the support department when assisting users with geometry import issues.
The design of foundations for offshore wind requires thousands of calculations. A medium-sized offshore wind farm nowadays has more than 100 locations, each with a slightly different soil profile and loading conditions. To reduce the number of calculations, engineers used to design for the worst possible case, which in the case of a 100-turbine farm means that at least 99 foundations will be larger than they need to be.
To truly optimize foundation design throughout the entire wind farm, engineers need to run more analyses in less time. In this context, automation is not a nice-to-have, but a necessity. The new Python scripting API for PLAXIS Monopile Designer enables these automated workflows. You can now write your automation scripts, calling on PLAXIS Monopile Designer, PLAXIS 3D, and/or OpenWindPower through their respective APIs, all using the same scripting language.
We are delivering with PLAXIS LE CONNECT Edition V21 Update 4 a collection of improvements based on your feedback. Visit the release notes on Bentley Communities to catch up on the latest PLAXIS LE changes.
Users are continuing to take advantage of the PLAXIS LE Slope Stability Solver API to build additional automation into the limit equilibrium components of their workflow.
So, update to our latest editions to benefit from these new features and software improvements today!
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