How to Run Your First FEA in SolidWorks Simulation

FEA Is a Tool, Not an Answer

SolidWorks Simulation (formerly COSMOSWorks) puts finite element analysis in the hands of mechanical engineers who are not FEA specialists. That is both its greatest strength and its greatest risk.

FEA results are only as reliable as the inputs: correct material properties, realistic boundary conditions, and a mesh fine enough to capture the stress gradients in critical regions. Get those wrong, and SolidWorks will happily give you a precise answer to the wrong question.

This guide walks you through a first static stress analysis with an emphasis on what the numbers actually mean and where the process can mislead you.

Step 1: Activate the Simulation Add-In

Go to Tools > Add-Ins and check SolidWorks Simulation in both columns (loaded and startup). If it is not listed, your SolidWorks license does not include Simulation — you need at minimum SolidWorks Simulation Standard.

After activation, a Simulation tab appears in the CommandManager. Click it to access the study tools.

Step 2: Create a New Study

Click New Study in the Simulation tab. For a first analysis, choose Static. Static analysis assumes loads are applied slowly and the structure reaches equilibrium — no vibration, no impact, no time-dependent effects.

Name the study descriptively: “Bracket_Static_100N_Vertical” tells you more than “Study 1.” You will thank yourself when you have ten studies in the same part.

Step 3: Assign Material

Right-click the part name in the Simulation tree and select Edit Material. SolidWorks has a built-in material library. For most structural steel, use AISI 1020 Steel or your actual material specification.

Critical properties for static FEA:

• Elastic Modulus (E): for steel, approximately 200 GPa. This controls how much the part deforms under load.
• Poisson’s Ratio (ν): for steel, approximately 0.28. This defines lateral strain behavior.
• Yield Strength (σ_y): for AISI 1020, approximately 210 MPa. This is the threshold above which permanent deformation occurs.
• Tensile Strength (σ_u): the ultimate failure point, approximately 380 MPa for 1020.

Do not use the default material unless it matches your actual specification. Material properties drive every result in the analysis.

Step 4: Apply Fixtures (Boundary Conditions)

Fixtures define where the part is constrained — where it cannot move. Right-click Fixtures in the Simulation tree and select Fixed Geometry for a simple analysis.

Select the faces that represent your mounting points. A bracket bolted to a wall: select the bolt hole faces or the back face (depending on how detailed you want to be).

Critical warning: fixtures are the most common source of unrealistic results. Fixing a face completely (all 6 degrees of freedom constrained) introduces artificial stiffness at that location. The stress near a fixed face is almost always artificially high — a phenomenon called “fixture stress concentration” or “boundary condition artefact.”

For a first analysis, this is acceptable. For design decisions, consider using pin connectors or remote loads instead of full fixed faces to better represent actual joint behavior.

Step 5: Apply Loads

Right-click External Loads and select Force (or Pressure, Torque, etc. as appropriate). Select the face where the load is applied, specify the direction and magnitude.

Be precise about direction. A 1000 N load applied vertically downward versus at 45 degrees gives very different results, especially for asymmetric geometry.

For a beam loaded at its free end, a 100 N downward force on the end face is straightforward. For more complex loading — distributed loads over an area, pressure from a fluid, gravity — use the appropriate load type. Do not approximate a distributed load as a point force unless the geometry makes that a valid simplification.

Step 6: Mesh the Model

Right-click Mesh in the Simulation tree and select Create Mesh. The default mesh is a starting point, not the final answer.

SolidWorks uses second-order tetrahedral elements (solid elements). The default element size is based on the overall part dimensions. For a first run, accept the default to see if the model runs. Then refine.

Mesh quality principles:

• Finer mesh in high-stress regions (notches, fillets, holes, re-entrant corners)
• Coarser mesh in low-stress regions (flat faces far from loads)
• Use Mesh Control (right-click Mesh > Apply Mesh Control) to locally refine specific faces or edges
• Run a mesh convergence study: halve the element size in the critical region and check if the peak stress changes by more than 5%. If it does, the mesh is not converged — keep refining.

Step 7: Run the Analysis

Click Run (the green arrow). For a small part with a default mesh, this takes seconds to minutes. For large assemblies with fine mesh, hours.

If the solver fails, the most common causes are: unconstrained degrees of freedom (fixture is insufficient), singularity in the geometry (zero-radius re-entrant corners), or mesh failure on very thin features. Check the error message and address the root cause.

Step 8: Interpret von Mises Stress Results

The default result plot is von Mises stress. This is a scalar representation of the combined stress state at each point, derived from the three principal stresses. It is used because it correlates with the onset of yielding in ductile materials.

The failure criterion for ductile metals is: material yields when von Mises stress ≥ yield strength.

Look for the maximum stress location (shown in red by default). Ask these questions:

1. Is the peak stress near a fixture? If yes, it may be a boundary condition artefact — ignore it and look at the next-highest stress region away from fixtures.
2. Is the peak stress at a fillet, hole, or notch? This is likely a real stress concentration. Calculate the theoretical stress concentration factor (Kt) for this geometry and verify the result makes physical sense.
3. Is the stress above the yield strength? If so, the design needs to change — larger cross section, better material, design modification to eliminate the stress concentration, or all three.

What the Safety Factor Means

The safety factor plot (Results > Define Factor of Safety Plot) divides the yield strength by the von Mises stress at each point:

SF = σ_y / σ_vonMises

SF = 1.0 means the material is exactly at the yield point. SF < 1.0 means yielding — the design has failed by yielding criterion. SF = 3.0 means there is three times the margin before yield.

What safety factor should you target? It depends on:

• Load certainty: if you know the load precisely, SF = 1.5 to 2.0 may be acceptable. If the load is uncertain, SF = 3.0 or higher.
• Failure consequences: a cosmetic bracket can fail at lower SF than a structural lifting point.
• Material variability: cast iron and some casting alloys have high variability and need higher SF.
• Industry standards: pressure vessels (ASME), cranes (FEM), machinery (ISO) all specify minimum safety factors. Know your applicable standard.

Common Beginner Mistakes

Key Takeaways

• FEA gives you a mathematical result for the model you built. If the model is wrong (wrong material, wrong fixtures, wrong loads), the result is precisely wrong.
• Always check whether peak stress is near a boundary condition — that stress is often an artefact, not a real problem.
• Run a mesh convergence study before making design decisions. Halve the element size in the critical region and confirm the result changes by less than 5%.
• von Mises stress ≥ yield strength means plastic deformation — redesign required. Use appropriate safety factors based on load certainty and failure consequences.
• SolidWorks Simulation is a powerful sanity-check tool. It is not a substitute for hand calculations and engineering judgment on critical applications.