Getting Started

The following walkthrough demonstrates a spinal implant linear elastic simulation using Intact for nTop. For full step-by-step details, watch the provided demo videos or open the completed *.ntop file.

Demo files:

Step 1: Connector Ribbon & Intact Blocks

Step 2: Intact Stress — Virtual Domain List Input

  • Insert the Intact Stress block (search or grab from the Connectors ribbon)

  • Fill in the Project Directory variable with a directory path from your machine to store simulation files

  • Create two Solid Domain blocks within the Virtual Domain List:

    1. ‘Implant Initial’ body + Solid Attribute with a PEEK isotropic material variable

    2. ‘Implant Insert’ body + Solid Attribute with a PEEK isotropic material variable

Step 3: Intact Stress — Boundary Conditions

  • Create a Boundary Condition List variable with three inputs:

    1. Displacement Restraint: Ux, Uy, Uz constrained on bottom CAD faces (CAD Face overload option)

    2. Vector Load: {0, 0, -1400} N on ‘Top Faces’ CAD faces variable

    3. Point Moment: “Remote Point” variable, {0, 0, -13} J on ‘Virtual Boundary by Body’ with ‘Top Interior Mask’ body variable (Boundary overload option) & ‘Flexible’ connector type

Step 4: Intact Preview

  • Insert the Intact Preview block (search or grab from the Connectors ribbon)

  • Insert the two implicit bodies for Simulation Body List:

    1. ‘Implant Initial’ body

    2. ‘Implant Insert’ body

  • Connect the Boundary Condition List variable from the previous step

  • Set Resolution to 10,000 and Geometric Tolerance to 0.5

  • Visualize the implicit implant geometry and point grid together — try different Preview Option choices from the dropdown to confirm boundary conditions are applied correctly

Step 5: Run Simulation & Post-Process

  • Run the simulation with 10,000 resolution and 0.5 geometric tolerance

  • Insert the Intact Resample block (search or grab from the Connectors ribbon):

    1. Connect the Intact Stress block variable from the previous step

    2. Connect the Project Directory variable used for Intact Stress

    3. Set the mesh from an implicit block with the ‘Implant Initial’ geometry and 0.2 mm tolerance

    4. Set the PEEK isotropic material

    5. Enter any unique ID as text

  • Insert the Intact Sample Points block (search or grab from the Connectors ribbon):

    • Same inputs as Resample but with a random point list inside the body instead of a mesh:

      1. Boolean union of ‘Lattice 1’ and ‘Lattice 2’ for the body

      2. 0.4 mm point spacing

  • Create field variables from the von Mises point map and displacement point map variables using the Sample Points block as input

Step 6: Field Driven Simulation

  • Create new implicit lattices with a ramped field thickness:

    1. Ramp input: von Mises field from the previous step

    2. Min/max in: based on the von Mises stress legend from the initial analysis

    3. Min/max out: 0.2/0.8 mm for ‘Lattice 1’, 0.1/0.6 mm for ‘Lattice 2’

  • Copy the Intact Stress block run in Step 5:

    1. Assign a unique Project Name input

    2. Replace the ‘implant initial’ Virtual Domain body with ‘Implant Field Driven’

    3. Run the simulation

  • Post-process in the same manner as Step 5, using the new Project Name and Intact Stress inputs

📌 Note: the mesh and point list for resampling should be based on the new implant/lattice geometry.