Structural Mechanics Module

New Functionality in Version 4.3

• Support for load cases:

• Loads and constraints can act conditionally in models using load groups and constraint groups, which you can include in load cases using various combinations of the defined groups.

• Use load groups for loads and other Neumann conditions. The loads can be scaled in the load cases using a scalar weight.

• Use constraint groups for constraints and other Dirichlet conditions.

• Available for the Solid Mechanics, Shell, Beam, Truss, and Plate interfaces.

• A new Membrane interface for modeling, for example, prestressed membranes, cladding on solids, and inflatable flexible bags (balloons). The Membrane interface can be seen as a representation of plane stress in a 3D geometry or as a shell without bending stiffness.

• New and redesigned periodic boundary conditions for solid mechanics and piezoelectric applications, including the following new types of periodic boundary conditions:

• General Floquet periodicity conditions.

• Cyclic symmetry condition for sector periodicity and dynamic cyclic symmetry.

• Also, an option to prescribe the periodic conditions on the entire displacement vector has been added (it is the new default option).

• Low-reflecting boundary condition, mainly intended for letting waves pass out from the model without reflection in time-dependent analysis. As a default, it takes material data from the domain in an attempt to create a perfect impedance match for both pressure waves and shear waves.

• Rigid connector improvements:

• Rigid connectors between shell edges are now available.

• Rigid connectors from shell and solid interfaces can be attached to each other.

• Linear buckling is now available for the Truss interface.

• The Prestressed Analysis, Frequency Domain study type is now supported also by the Truss interface.

• The rate of strain (Ld) and spin (Lw) tensors are now available as predefined variables (on the spatial frame) in the solid interfaces.

• Strain energy density is now computed as a result also in the Truss, Beam, Shell, and Plate interfaces.

• Shell curvature data is now available as variables, which you can use to modify material, thickness, or initial stress for deep drawn sheets.

• Gauss point results are now available for almost all stress results in Structural Mechanics, and all Gauss point results have been moved to separate groups in the plot list.

• The use of geometric nonlinearity is now controlled by a setting in the study step also for the Shell and Truss interfaces.

New Models

• Sliding Wedge: This model is a friction benchmark.

• Snap Hook Penalty: Model that shows an alternative simplified contact formulation.

• Truss Tower Buckling: A linear buckling example using the Truss interface.

• Vibrating Membrane: A verification example using the Membrane interface.

• Nonlinear Magnetostriction

• Turbine Stator

Backward Compatibility vs. 4.2a

• The nonlinear structural mechanics functionality is version 4.2a is now available in the Nonlinear Structural Materials Module, which is an add-on to the Structural Mechanics Module. See Nonlinear Structural Materials Module. This applies to hyperelastic and elastoplastic materials, which are now available in the Nonlinear Structural Materials Module.

• There is now a single redesigned Prescribed Rotation node for shells and plates that works with both linear and geometrically nonlinear material.

Backward Compatibility vs. Version 3.5a

Plane Stress

Version 4 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 display strains and stresses. Displacements are correctly displayed.