New Functionality

  • A flexible definition of elastic material data enables the solid mechanics interfaces to support bulk modulus and shear modulus, Lamé constants, and pressure-wave and shear-wave speed in addition to Young’s modulus and Poisson’s ratio.
  • Custom hyperelastic material models can be created by specifying a strain energy function in terms of deformation tensor components and invariants.
  • A flexible 2D solid mechanics interface allows you to switch between plane stress and plane strain approximations at any point during modeling. For example, it is now easy to compare the results with plane strain and plane stress assumptions.
  • Prescribed velocity and acceleration boundary conditions are now available also in transient analysis. Previously, these conditions were available only in the frequency domain.
  • A new rigid connector boundary condition (only in 3D in version 4.0) makes it possible to apply kinematic constraints, forces, and moments on boundaries assumed to displace as a rigid body.
  • A new 3D shell element formulation based on first-order or second-order Lagrange shape functions on both triangles and quadrilaterals gives improved accuracy. Curved surfaces and mixed solid-shell models, in particular, are improved. In addition, the new shell elements are fully multiphysics-enabled and support large deformations.
  • Frequency-domain and time-domain modal solvers lets you run fast frequency sweeps and transient response analyses on reduced models.

Backward Compatibility

All backward compatibility issues are planned to be solved for version 4.0a unless explicitly stated.

Cross-Section Library

The cross-section library for beams is not available in version 4.0. This is planned for version 4.1.


Damping is not available for shells, beams, and trusses in version 4.0. Meanwhile, you can use complex elastic moduli to apply damping in the frequency domain.

Plane Stress

Version 4.0 represents the out-of-plane strain as a separate degree of freedom. Plane stress models made with version 3.5a need to be re-solved to correctly compute strains and stresses. Displacements are correctly computed.

Plate Interface

The 2D Plate physics interface is not yet available. Plate application modes in version 3.5a models are not imported into version 4.0.

You can use the shells to do plate modeling using a planar 3D geometry.


Symbols in the graphics window representing constraints and loads are not yet available in version 4.0. Symbols will be available in version 4.1.

Principal Stress/Strain Plots

Principal stress/strain plots are not yet available in version 4.0.