Altair Multiscale Designer 2026 Release Notes

New Features

Multiscale Material MATMDS is supported in OptiStruct Explicit
OptiStruct 2026.0 supports Multiscale Designer materials as MATMDS, using the same input format as OptiStruct implicit analysis. This new feature enables the usage of all Multiscale Designer single and Multiscale materials with OptiStruct explicit analysis.
Inverse General Approach available in all Material Templates
In addition to the specific inverse methods in the continuous reinforced and discontinuous reinforced material template, the general inverse method can be selected enabling the choice of optimizing any material parameter against test data. While the specific inverse method is the most efficient to use for any standard combination of matrix and fiber, the general inverse approach provides the freedom to define an inverse characterization fitting better for example to non-standard matrix fiber combination.




Enhancements

Fiber Orientation Tensor Handling
The handling of Fiber Orientation Tensors (FOT) is enhanced to a full 3D approach. This enhancement improves the handling of the out of plane fibers and ensures that a 3D Random FOT ( a11 = a22 =a33 = 0.333 ) is leading to a 3D quasi-isotropic homogenized stiffness ( E1=E2=E3 ) in opposite to the prior approach. While the results with that approach will be more accurate, existing material models will provide different results with version 2026.0. More details on the method can be found in the User Manual.
Since there is no benefit from the quality of results or numerical performance point of view to keep the old FOT handling available, it is recommended to rerun any inverse fit versus test data again with version 2026.0 and update the Multiscale Designer material model.

Resolved Issues

  • In the inverse general and inverse combined approach, an approximate modulus is computed when importing strain-stress data.
    Figure 1.


  • Similar file names of the virtual tests lead to an error displaying the result.