Selecting Solid Stress Physics Models

Activate physics models for stress analysis and select the material laws that define the behavior of the solid.

Create a physics continuum and assign it to the region that represents the solid material.

In the physics continuum, activate the following physics models:


Group Box	Physics Model
Space	Three Dimensional
Time	For static analysis, activate the Steady model Static simulations include time-independent analyses and time-dependent analyses for which the time scales to load or to unload the structure are very long compared to the time scales for propagation of flexural or sound waves. See Solution Methods. For dynamic analysis, where the transients due to the low-frequency flexural waves or high-frequency sound waves are important, activate the Implicit Unsteady model. For quasi-static analysis, where you seek the static solution while having the option to apply the loads progressively over time, activate the Implicit Unsteady model in Static Analysis mode. See Solid Stress Solver Reference.
Material	To model a single material solid part, activate the Solid model. To model an assembly of solid parts of different materials, activate the Multi-Component Solid > Multi-Part Solid model.
Optional Models	Solid Stress
Optional Models	Material Law Models (selected automatically)

Activate additional models from the Optional Models group box, based on analysis requirements:
- To add mass and stiffness proportional damping, activate the Rayleigh Damping model.
- To account for gravity, activate the Gravity model.
- By default, the Solid Stress model accounts for small deformations in the structure (linear geometry). To model nonlinearities due to large displacements and rotations, activate the Nonlinear Geometry model. You also require this model when modeling hyperelastic materials.
- To account for thermal expansion due to changes in the solid temperature, activate one of the following models:
  - Finite Element Solid Energy model—solves for the solid temperature in conjunction with solid displacement. You can use this model for solid-only simulations, or for simulations that model conjugate heat transfer (CHT) between a solid and a fluid.
  - Specified Temperature Load model— allows you to apply a temperature load on the solid region using a constant value, field function, or tabular values. This approach is also suitable for temperature loads that were computed on a different mesh representation (consider, for example, the solid temperature computed on a finite volume mesh using the Segregated Energy or Coupled Energy models).
- To use electromagnetic forces as body loads for stress analysis, activate the Electromagnetism model and any relevant submodels. The Solid Stress model is compatible with the Finite Element Magnetic Vector Potential model, the Electrodynamic Potential model, and their optional models. For more information on setting up electromagnetic analyses, see Modeling Magnetic Fields and Modeling Electric Currents.
For details on the properties and dependencies of the solid stress physics models, see Solid Stress Reference.

If you require to analyze the solid displacement induced by fluid forces, see Fluid Structure Interaction General Workflow.
Examples of model selections are shown below:
- (1)—Static stress analysis of a multi-material solid, including the effect of gravity, with the assumption of small deformations (linear geometry).
- (2)—Static stress analysis of a single-material solid, including non-linearities due to large displacements and rotations (nonlinear geometry).
- (3)—Dynamic stress analysis of a single-material solid, subject to fluid forces at the fluid-structure interface (FSI). The physics continuum representing the fluid is not shown in example (3).

At mapped contact interfaces between solid parts, specify the type of mechanical interaction:

Select the [Solid/Solid Interface] > Physics Conditions > Mechanical Interaction node and set Method to one of the following:
- Bonded—displacements are continuous across the interface. For interfaces between different materials, Simcenter STAR-CCM+ preserves discontinuities in the strain.
- Small Sliding Frictionless—the surfaces at the two sides of the interface can slide over each other in the interface plane. Simcenter STAR-CCM+ prevents movement in the normal direction. This option is suitable for interfaces between flat surfaces, with the assumption of small sliding.
For more information, see Interface Settings.

For solid-solid interfaces with Bonded mechanical interaction, select the method that Simcenter STAR-CCM+ uses for constraining the surfaces:

Select the [Solid/Solid Interface] > Physics Conditions > Constraint Mapping node and set Method to either Node to Surface or Surface to Surface.
In general, the Surface to Surface method is more accurate, but it requires higher computational effort. For more information, see Interface Settings.