Connector Blocks

Intact Stress Block

This block has the following inputs:

  • (optional) Project Name: A unique simulation name to store multiple runs in the same directory for additional post-processing or resampling.

  • (optional) Project Directory: A directory to save the simulation files to for additional post-processing or resampling.

  • Virtual Domain List: Accepts a list of Solid Domain blocks using the implicit body overload.

  • Simulation Geometry: Specifies the type of geometry used in simulation, takes: voxel grid, surface mesh, or direct on implicit.

  • Geometric Tolerance: The fidelity used for Simulation Geometry, voxel size or mesh tolerance.

  • Boundary Condition List: Accepts a list of nTop boundary conditions using either

    1. CAD Face overload

    2. Boundary overload using an implicit input via Virtual Boundary by Body

  • Use Inertial Relief?: Boolean toggle to use inertial relief in absence of sufficient FE contraints.

  • Basis Order: Selection of linear or quadratic order for the finite element analysis.

  • Resolution: Simulation fidelity, approximate number of elements to use.

  • Use Cell Size?: Boolean toggle to use cell size directly instead of resolution.

  • Cell Size: Simulation fidelity, edge length of each element

  • Solver Type: Selection of default, direct, or iterative solver.

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Intact Thermal Block

This block has the following inputs:

  • (optional) Project Name: A unique simulation name to store multiple runs in the same directory for additional post-processing or resampling.

  • (optional) Project Directory: A directory to save the simulation files to for additional post-processing or resampling.

  • Virtual Domain List: Accepts a list of Solid Domain blocks using the implicit body overload.

  • Simulation Geometry: Specifies the type of geometry used in simulation, takes: voxel grid, surface mesh, or direct on implicit.

  • Geometric Tolerance: The fidelity used for Simulation Geometry, voxel size or mesh tolerance.

  • Boundary Condition List: Accepts a list of nTop boundary conditions using either

    1. CAD Face overload

    2. Boundary overload using an implicit input via Virtual Boundary by Body

  • Basis Order: Selection of linear or quadratic order for the finite element analysis.

  • Resolution: Simulation fidelity, approximate number of elements to use.

  • Use Cell Size?: Boolean toggle to use cell size directly instead of resolution.

  • Cell Size: Simulation fidelity, edge length of each element

  • Solver Type: Selection of default, direct, or iterative solver.

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Intact Modal Block

This block has the following inputs:

  • (optional) Project Name: A unique simulation name to store multiple runs in the same directory for additional post-processing or resampling.

  • (optional) Project Directory: A directory to save the simulation files to for additional post-processing or resampling.

  • Virtual Domain List: Accepts a list of Solid Domain blocks using the implicit body overload.

  • Simulation Geometry: Specifies the type of geometry used in simulation, takes: voxel grid, surface mesh, or direct on implicit.

  • Geometric Tolerance: The fidelity used for Simulation Geometry, voxel size or mesh tolerance.

  • (optional) Boundary Condition List: Accepts a list of nTop boundary conditions using either

    1. CAD Face overload

    2. Boundary overload using an implicit input via Virtual Boundary by Body

  • Desired Eigenvalues: Specifies the number of eigenvalues to solve for.

  • Basis Order: Selection of linear or quadratic order for the finite element analysis.

  • Resolution: Simulation fidelity, approximate number of elements to use.

  • Use Cell Size?: Boolean toggle to use cell size directly instead of resolution.

  • Cell Size: Simulation fidelity, edge length of each element

  • Solver Type: Selection of default, direct, or iterative solver.

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Intact Thermoelastic

This block has the following inputs:

  • (optional) Project Name: A unique simulation name to store multiple runs in the same directory for additional post-processing or resampling.

  • (optional) Project Directory: A directory to save the simulation files to for additional post-processing or resampling.

  • Virtual Domain List: Accepts a list of Solid Domain blocks using the implicit body overload.

  • Simulation Geometry: Specifies the type of geometry used in simulation, takes: voxel grid, surface mesh, or direct on implicit.

  • Geometric Tolerance: The fidelity used for Simulation Geometry, voxel size or mesh tolerance.

  • Boundary Condition List: Accepts a list of nTop boundary conditions (linear elastic and thermal) using either

    1. CAD Face overload

    2. Boundary overload using an implicit input via Virtual Boundary by Body

  • Use Inertial Relief?: Boolean toggle to use inertial relief in absence of sufficient FE contraints.

  • Basis Order: Selection of linear or quadratic order for the finite element analysis.

  • Resolution: Simulation fidelity, approximate number of elements to use.

  • Use Cell Size?: Boolean toggle to use cell size directly instead of resolution.

  • Cell Size: Simulation fidelity, edge length of each element

  • Solver Type: Selection of default, direct, or iterative solver.

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Intact Resample

This block has the following inputs:

  • Intact Result: The Intact Stress, Intact Thermal, Intact Modal, or Intact Thermoelastic block to be resampled

  • (optional) Project Name: The same Project Name optionally used in the Intact Stress block.

  • Project Directory: The same Project Directory files were optionally stored in with Intact Result

  • Resampling Mesh List: A list of meshes to visualize/sample the solution onto.

  • Material List: A list of materials used for each mesh (should be the same as in Intact Result). Note these lists must be the same length

  • Resampling ID: Unique file identifier (for multiple resampling instances of the same Intact Result)

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Intact Sample Points

This block has the following inputs:

  • Intact Result: The Intact Stress, Intact Thermal, Intact Modal, or Intact Thermoelastic block to be resampled

  • (optional) Project Name: The same Project Name optionally used in the Intact Result block.

  • Project Directory: The same Project Directory files were optionally stored in with Intact Result

  • Sampling Points: A list of points to visualize/sample the solution onto.

  • Material: A material used for sampling the points (should be the same as in Intact Result).

  • Resampling ID: Unique file identifier (for multiple resampling instances of the same Intact Result)

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Intact Preview

This block creates a point list that is used to preview where the immersed grid is and where boundary conditions and internal conditions are applied. This block has the following inputs:

  • Simulation Body List: Accepts a list of implicit bodies which indicate the simulation components/domain.

  • Geometric Tolerance: The fidelity used for Simulation Geometry, voxel size or mesh tolerance.

  • Boundary Condition List (Optional): Accepts a list of nTop boundary conditions (linear elastic and thermal) using either

    1. CAD Face overload

    2. Boundary overload using an implicit input via Virtual Boundary by Body

  • Resolution: Simulation fidelity, approximate number of elements to use.

  • Use Cell Size?: Boolean toggle to use cell size directly instead of resolution.

  • Cell Size: Simulation fidelity, edge length of each element

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By selecting a Preview Option, you can preview the simulation setup. In the following image, a connecting rod will be simulated, and where the restraints will be applied is denoted by the blue region and where the loads will be applied is denoted by the orange region.

preview of simulation domain showing where loads and restraints will be applied

Block Inputs

Domain

The Virtual Domain List input takes a list of virtual domains consisting of a Solid Domain block, which also contains a Solid Attribute block carrying the material properties.

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Boundary Conditions

The Boundary Condition List input uses default ntop boundary condition blocks with either a CAD Face List overload or a virtual boundary by body.

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Selection Region / Mask on Implicit Boundary Conditions

In nTop, since we’re working with implicit geometry, there isn’t an explicit notion of discrete “faces” that you can select like in CAD/B-rep models. The boundary is defined implicitly, so we need a way to localize where to apply conditions.

The “mask” is just a selection region in space. We intersect that region with the implicit boundary, and the portion of the boundary inside the mask becomes the face where the BC is applied. See the figure below for a 2D example.

Implicit BC Mask

Simulation Settings

Intact.Simulation allows customizations to support rapid coarse as well as accurate fine simulation as desired. The following Simulation Settings are available:

  • The Basis order is the order of finite elements used. It can be Linear (default) or Quadratic.

    • Note that with quadratic elements, far fewer elements are needed to compute an accurate solution. However, quadratic elements are much more expensive in terms of time and memory resources than linear elements.

    • Recommendation:

      • Quadratic elements are suited for bending dominant problems like thin shells and beam-type structures.

  • Specify Precision Type and Precision Value for the desired accuracy/speed of the simulation.

    • Resolution is the target number of finite elements. An iterative process determines a Cell size that achieves approximately the specified number of elements. The simulation log in the Project directory contains the exact cell size and number of finite elements used in the simulation.

    • You can toggle on Use Cell Size? to directly specify the Cell Size instead of the Resolution, for example, when you want to resolve the correct behavior of certain geometric features. Note that when Use Cell Size? is On, Resolution is ignored.

    • The immersed grid for the simulation is stored in _solution.vtu in the project folder and can be visualized if desired (using Paraview).

    • Recommendation:

      • We recommend using Resolution if you are unsure of the cell size. A small Cell Size can quickly result in a large number of finite elements and long solve times.

  • Solver Type is the linear solver used in the simulation with the following options:

    • Direct “directly” solves the linear system and is very robust but typically consumes more memory, which can be a problem for high resolution or small cell size.

    • Iterative solves the linear system “iteratively” and uses less memory than Direct. They are suited for high resolutions.

    • Default: Sets the solver automatically based on Basis order and Resolution .

      • For static structural Linear elements, default is Iterative Solver for resolution greater than 200K and Direct Solver for less than 200K. Note that if the Precision Type is cell size, the default is always Iterative for linear elements. Quadratic elements, it defaults to Direct solver for all resolutions or cell sizes.

      • Thermal solvers default to Direct, if desired Iterative can be manually selected for some cases which utilize large amounts of memory.