This section contains information about feature enhancements that can affect program behavior or analysis results in ways that you may not expect. Also covered are known incompatibilities, notable issues and defects that have been resolved, and information about replacement capabilities for features that have been removed.
The following topics offer supplemental 2025 R2 product-update information presented by the Mechanical APDL development and testing teams:
If you are upgrading across several releases, you may find it helpful to consult the Update Guide sections of the archived release notes for Mechanical APDL.
For information about past, present, and future operating system support, see the Platform Support section of the Ansys Website.
Mechanical APDL Release 2025 R2 can read database files from all prior Mechanical APDL releases. Due to ongoing product improvements and defect resolutions, however, results obtained from old databases running in new releases may differ somewhat from those obtained previously.
The following Mechanical APDL feature updates in Release 2025 R2 are known to produce program behaviors or analysis results that differ from those of the prior release:
9.2.1. Change in Harmonic Analysis with CORIOLIS,ON
In a full harmonic analysis with Coriolis effect activated in the rotating reference frame (CORIOLIS,ON), the centrifugal force is not taken into account. In past releases, it was considered a harmonic load.
If degree of freedom coupling or constraint equations are present, the enforced motion calculation now provides more robust solutions. For large models, it may lead to longer computation time.
If the rigid body modes generated using the geometry
(RIGID_CALC = 1) are found to be insufficiently
accurate, the program calculates the rigid body modes again using an
eigensolver.
In Special Version and Service Package releases, the ADAMS reader now automatically truncates the release name in MNF files to ensure they do not exceed the 16-character limit. This ensures compatibility and prevents crashes during file processing.
No incompatibilities were introduced this release.
The following incompatibilities with prior releases are known to exist at Release 2025 R2:
The following issues are known to exist at Release 2025 R2:
Linear Perturbation analysis limitation – The total tangent stiffness matrix obtained from a Linear Perturbation basis analysis may include stress stiffness and load stiffness contributions (geometric stiffness). If the geometric stiffness contribution is significant, then the total tangent stiffness matrix, when used in a Linear Perturbation downstream analysis, may produce reaction forces not satisfying the equilibrium with the external forces.
GPU acceleration hangs on AMD Cards with small models – When running certain small models with the GPU accelerator enabled on AMD cards, specifically using three or more processes, the program may run very slowly and appear to hang.
Workaround: To avoid this issue, create the following environment variable:
GPU_MAX_HW_QUEUES=2
Automatic initialization in curve fitting requirement – To use automatic initialization in curve fitting for hyperelastic models with Prony series viscoelasticity, the latest AML Python module must be installed beforehand.
For issues discovered following publication of this document, see Mechanical APDL in the Ansys Known Issues and Limitations.
The following notable issues and defects for Mechanical APDL have been resolved at Release 2025 R2:
| ID | Resolution Description |
|---|---|
| 1174494 | An instability when using a *PYTHON block containing Mechanical APDL errors in batch mode has been resolved. |
| 1247948 | The instability when running ans_admin.exe without an Intel compiler has been resolved. |
| 1172441 | The problem with left-clicking external links in the documentation, which previously did not open the intended website, has been fixed. Left-clicking an external link now correctly opens the website in a new tab. |
| 1159211 | The limitation regarding nesting while using Open MPI on AMD GPU devices has been documented. For more information, see GPU Accelerator Capability in the Parallel Processing Guide. |
| 1139164 | The issue with using the PCG solver on AMD GPU devices has been resolved. |
| 1164591 | The ADAMS reader previously crashed when processing MNF files containing release names that were longer than 16 characters in Special Version (SV) and Service Package (SP) releases. This issue has been resolved. For SV and SP releases, the release names in MNF files are now automatically truncated in the output. For more details, see Change in MNF File for Special and Service Releases. |
If a legacy Mechanical APDL feature has been removed at Release 2025 R2, this section provides information about the Mechanical APDL replacement feature, its functional equivalent in another Ansys product, or another workaround.
Legacy features that have been archived also appear here. While archived features remain available for use, technical enhancement is unlikely to occur, and better alternatives are available and recommended in most cases.
The following topics are available:
The MSAVE command has been undocumented. Advancements to the Preconditioned Conjugate Gradient (PCG) solver and PCGOPT command make MSAVE obsolete.
KEYOPT 18 has been undocumented for the CPT elements. When defining the nonlocal damage material models (generalized damage, microplane regularized damage, such as elastic and coupled damage-plasticity, and regularized anisotropic damage), you no longer need to define KEYOPT 18 for CPT elements. Previously, KEYOPT 18 had to be set to certain model-specific values to activate the required extra degree(s) of freedom. Now, the extra DOF(s) are automatically activated with a non-zero length scale parameter definition.