FEM SolverZ88
Appearance
|
|
| Menu location |
|---|
| Solve → Solvers → Solver Z88 |
| Workbenches |
| FEM |
| Default shortcut |
| S Z |
| Introduced in version |
| - |
| See also |
| FEM tutorial |
Description[edit | edit source]
The SolverZ88 command enables usage of the Z88 solver. It may be used for:
- Setting analysis parameters
- Selecting working directory
- Running the Z88 solver
introduced in 1.2: The Z88 solver implementation has been completely refactored, and this page has been updated accordingly.
Installation[edit | edit source]
To use the Z88 solver, the open-source version of Z88 (Z88OS or Z88Adria - see Notes for more details) needs to be installed:
- Download the ZIP package with the code, binaries and documentation of either version:
- Z88OS: official Z88OS repository or forked Z88OS repository
- Z88Adria: Z88Adria download page.
- Extract the ZIP contents to a folder of your choice.
- In the FEM preferences, go to the Z88 tab and set the path to the z88r binary. If you are on Windows, this would be the path to the file z88r.exe that is in the subfolder \bin\win64 for Z88OS or \z88adria_windows for Z88Adria.
Usage[edit | edit source]
- Create an
Analysis container.
- There are several ways to invoke the command:
- Press the
Solver Z88 button.
- Select Solve → Solvers →
Solver Z88 option from the menu.
- Use the keyboard shortcut: S then Z.
- Press the
- Double-click on the
SolverZ88 object to prepare an analysis run.
- Optionally, check the Working directory box, click Write and Edit to modify the input files before submitting an analysis.
- Optionally, select the Solver type.
- Click Apply to run an analysis.
Properties[edit | edit source]
- DataExclude Bending Stiffness - replaces beams with trusses, currently always checked because beams are not yet supported
- DataModel Space:
- 3D - uses 3D shell elements
- plane stress - uses 2D plane stress elements
- axisymmetric - uses 2D axisymmetric elements
- plate - uses 3D plate elements
- DataShell Flag - IHFLAG value: set to 2 or 3 for thin shells and to 4 for very thin shells
- DataAnalysis Type:
- static
- test
- DataDisplace Mesh - deform the mesh by the displacement field
- DataIntegration Order Hexa - displacement integration order for hexa elements
- DataIntegration Order Quad - displacement integration order for quad elements
- DataIntegration Order Tetra - displacement integration order for tetra elements
- DataIntegration Order Tria - displacement integration order for tria elements
- DataIteration Maximum - MAXIT value: maximum number of iterations for iterative solvers
- DataMatrix Maximum - MAXGS value: maximum number of entries in the stiffness matrix
- DataRelaxation Factor - ROMEGA value: convergence acceleration parameter for SOR pre-conditioner
- DataResidual Limit - EPS value: it is compared to the norm of the residual vector
- DataShift Factor - RALPHA value: convergence acceleration parameter for SIC pre-conditioner
- DataSolver Type:
- choly - direct Cholesky solver recommended for small structures
- sorcg - sparse matrix iterative SORCG solver recommended for large structures
- siccg - sparse matrix iterative SICCG solver recommended for large structures
- DataVector Maximum - MAXKOI value: maximum number of entries in the coincidence vector
Supported finite element types[edit | edit source]
The following types of finite elements are supported by the Z88 solver implementation:
- 2-node 3D truss,
- 8-node and 20-node hexahedron,
- 4-node and 10-node tetrahedron,
- 6-node triangle and 8-node quadrangle - 3D shell and plate, 2D plane stress and axisymmetric formulations.
Linear triangles and quadrangles are not supported at all. Beam elements are not yet supported.
Notes[edit | edit source]
- Z88Adria has the same capabilities/limitations as Z88OS, but doesn't launch its GUI when running the solver from FreeCAD, so Z88Adria is currently the preferred choice.
- Pressure applied to edges of axisymmetric models must be given as in a corresponding 3D model, i.e. in units of force per unit area; the solver converts it to an equivalent force per unit length by multiplying the pressure by (where R is the x-coordinate of the element's middle node).
- For plate elements, the degrees of freedom are in order: Z displacement and rotations and (in deg).
- A test analysis mode is available. It provides information about the solver parameters. This information is loaded into the text document object.
Limitations[edit | edit source]
- Currently, only displacements (in mm), nodal forces, and nodal moments are provided as contour map results. Stress values are loaded into the text document object.
- The 3D truss elements require some additional considerations. In case of errors and missing results when using them, the following steps should be taken:
- make sure the structural member is meshed with only one such element (adjust the min and max element size to enforce that),
- apply displacement boundary condition to the whole member, constraining the lateral displacements,
- use the Cholesky solver.
Preferences[edit | edit source]
See the Z88 preferences for the possible solver settings, such as the used solver method.
- Materials: Solid Material, Fluid Material, Non-Linear Mechanical Material, Reinforced Material (Concrete); Material Editor
- Element Geometry: Beam Cross Section, Beam Rotation, Shell Plate Thickness, Fluid Section for 1D Flow
- Electromagnetic Boundary Conditions: Electrostatic Potential Boundary Condition, Current Density Boundary Condition, Magnetization Boundary Condition, Electric Charge Density
- Fluid Boundary Conditions: Initial Flow Velocity Condition, Initial Pressure Condition, Flow Velocity Boundary Condition
- Geometrical Analysis Features: Plane Multi-Point Constraint, Section Print Feature, Local Coordinate System
- Mechanical Boundary Conditions and Loads: Fixed Boundary Condition, Rigid Body Constraint, Displacement Boundary Condition, Contact Constraint, Tie Constraint, Spring Boundary Condition, Force Load, Pressure Load, Centrifugal Load, Gravity Load
- Thermal Boundary Conditions and Loads: Initial Temperature, Heat Flux Load, Temperature Boundary Condition, Body Heat Source
- Overwrite Constants: Constant Vacuum Permittivity
- Mesh: Mesh From Shape by Netgen, Mesh From Shape by Gmsh, Mesh Boundary Layer, Mesh Refinement, Mesh Group, Erase Elements, FEM Mesh to Mesh
- Solve: Solver CalculiX, Solver Elmer, Solver Mystran, Solver Z88; Mechanical Equations: Elasticity Equation, Deformation Equation; Electromagnetic Equations: Electrostatic Equation, Electricforce Equation, Magnetodynamic Equation, Magnetodynamic 2D Equation, Static Current Equation; Flow Equation, Flux Equation, Heat Equation, Solver Job Control, Run Solver
- Results: Purge Results, Show Result, Apply Changes to Pipeline, Post Pipeline From Result, Pipeline Branch, Warp Filter, Scalar Clip Filter, Function Cut Filter, Region Clip Filter, Contours Filter, Glyph Filter, Line Clip Filter, Stress Linearization Plot, Data at Point Clip Filter, Calculator Filter; Filter Functions: Plane, Sphere, Cylinder, Box; Data Visualizations: Create Lineplot, Create Histogram, Create Table
- Utilities: Clipping Plane on Face, Remove All Clipping Planes, FEM Examples; Clear FEM Mesh, Display Mesh Info
- Additional: Preferences; FEM Install, FEM Mesh, FEM Solver, FEM CalculiX, FEM Concrete; FEM Element Types
- Getting started
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