Your first simulation

This page walks through a complete simulation end to end. If you prefer to learn by reading the individual settings, see Input reference and Output reference instead.

The example here is the built-in Compact Tension (CT) specimen — a small rectangular plate with a pre-cut notch that is pulled apart at two points. It is the textbook experiment for studying how cracks grow, and it is a great first model because you can watch a crack start at the notch tip and travel across the plate.

1. Pick a model

When you open PeriHub the built-in models are shown. Select Compact Tension from the list. Its default settings are already reasonable, so you can move on without changing anything yet.

If you ever want to start from a blank slate, use the Reset data button to clear the current model.

2. Generate the model

In the Model section of the Setup panel, press Generate model. PeriHub computes the mesh — the network of tiny points that stand in for your part — and draws it in the Results panel. A crack or notch is already part of the geometry for this model.

Tip: the first generation can take a few seconds while the mesh is built. A spinner shows that work is in progress.

3. Inspect the mesh

Still in the Results panel, switch the view to Mesh to look at the part from different angles. Use your mouse — drag to rotate, scroll to zoom, and right-drag (or two-finger drag on a touchpad) to pan. This is a good moment to check that the mesh looks dense enough; see the next step if the mesh looks coarse.

4. Set the mesh size

Open the Discretization panel. The setting that matters most here is the number of points per unit of height — a higher number means a finer, more accurate mesh, at the cost of a longer run. The built-in model already sets this to a good value, but if your results look rough or you want more detail, raise it. If your run is slow, lower it.

5. Choose the material

Open the Material panel and pick a material. For a first simulation, the default isotropic material is fine — it is a reasonable choice for many materials and needs no further input.

Once you pick a material, open the Blocks panel. Blocks are the regions the part is split into; here you attach a material and a damage model to each one. Built-in models come with their blocks pre-configured.

6. Add boundary conditions

A simulation needs to know what is held fixed and what is allowed to move. The Boundary conditions panel handles this. For the CT specimen, the two holes where the machine grips the plate are held in place, and the plate is pulled in the vertical direction until the crack grows.

These are already set up for the built-in model, so you can leave them as they are. If you build your own model, you will need to add these conditions yourself.

7. Submit the job

When your model looks right, switch to the Results panel and press Submit model. PeriHub prepares everything and hands the work to the solver.

As the simulation runs, the Text view at the bottom right shows the live log — you can watch the progress there. If something goes wrong, use Cancel job to stop it. If it finishes cleanly, the log will show an Exit Success message.

Submitting a job requires the solver to be running. When you run PeriHub yourself, start it with docker compose up perilab -d (see Getting Started).

8. View the results

After the job finishes, the Results panel shows your saved fields. Switch between the Mesh and Plot views to inspect them, and use the mesh view to zoom in on the crack tip.

9. Plot a curve

Fracture experiments are usually summarized by a curve. For the CT specimen, a force versus displacement curve tells you how the plate responds as the crack grows.

1. Open the Plot dialog from the Results panel.
2. Choose the property to plot (force) on one axis and the independent variable (displacement) on the other.
3. Press Add to results.

The chart appears in the Results panel.

10. Analyze the crack

PeriHub can automatically detect and characterize cracks from the broken bonds in your simulation. Use the fracture analysis tools in the Results panel to extract the crack path and its length over time.

11. Save your work

When you have something you want to come back to, save it:

• Save as JSON — export the full model so you can reopen and edit it later.
• Save config — export the settings only, to reuse on other models.
• Download results — save the computed data as a .tar.gz archive.

What’s next

You now know the complete loop. Try changing one thing — a finer mesh, a different material, or a different boundary condition — and re-run to see how the crack behavior changes. See Input reference for what every setting means, and Output reference for how to explore and save results.