Using 32-bit or 64-bit dynamic-link libraries (DLL) to run user-defined soil model (UDSM)

Since the release of PLAXIS 2D 2017 and PLAXIS 3D 2016, both calculation kernel and graphical user interface (GUI) are designed to use 64-bit processors. Due to this, only 64-bit dynamic-link libraries (DLL) can be used to run a user-defined soil model (UDSM) in PLAXIS.

Having compiled a 64-bit .dll file, it should be placed in the folder "udsm", located in PLAXIS installation folder.

For further information, please refer to Plaxis user defined soil models/.

Previous versions of PLAXIS

In previous versions of PLAXIS, a 64-bit kernel is used in conjunction with a 32-bit GUI. To run a UDSM, it is, therefore, necessary to have a 64-bit version of the UDSM to interact with the kernel and a 32-bit version to interact with the GUI. The following is recommended:

• compile the UDSM as a 32-bit DLL file (e.g., YourModel.dll);
• compile also the UDSM as a 64-bit DLL file; give the same name as used for 32-bit DLL file, followed by "64"(e.g. YourModel64.dll);

Please note that it is necessary to compile the UDSM code as 32-bit and 64-bit DLL, not just to rename one of the |DLL files. Moreover, please note that both 32-bit and 64-bit DLL files should be placed in the folder "udsm", located in PLAXIS directory folder.

Providing that (1) the DLL are properly compiled and (2) their names are correctly set and (3) the DLL files are places in the correct directory, the 32-bit DLL will interact with the GUI, while the 64-bit DLL will interact with the kernel to run the Finite Element calculation.

Alternatively, to make use of only the 32-bit DLL it is possible to use the 32-bit calculation kernel by disabling the 64-bit version available in the PLAXIS directory folder. As detailed below, the easiest strategy consists of renaming the 64-bit calculation kernel, which will disable it. Please note that, by using a 32-bit kernel, only a 32-bit DLL is necessary. Please note also that, to restore the 64-bit behaviour, the kernel file should be renamed to its original name.

Disabling the 64-bit kernel in PLAXIS 2D AE, PLAXIS 2D 2015 and PLAXIS 2D 2016

Please go to the PLAXIS installation folder and search for a subfolder called "64". Open the subfolder and rename the file "plasw64.exe" to, e.g., "_plasw64-backup.exe".

Disabling the 64-bit kernel in PLAXIS 2D 2011, 2012 and 2D Classic

Please go to the PLAXIS installation folder and search for the file "plasw64.exe". Having found it, please rename it to, e.g., "_plasw64-backup.exe".

Disabling the 64-bit kernel in PLAXIS 3D 2012/2013/AE

Please go to the PLAXIS installation folder and search for the file "plasw364.exe". Having found it, please rename it to, e.g., "_plasw64-backup.exe".