SimScale Cloud FEA: Static Structural, Dynamic, and Thermal Analysis

SimScale Cloud FEA: Static Structural, Dynamic, and Thermal Analysis

When I first tried SimScale for structural analysis, I was skeptical. Code_Aster as the solver? I'd never heard of it outside of academic circles. But after running a few benchmarks against ANSYS, I was surprised — the results matched within 2% for linear static, and the nonlinear contact worked fine too. It's not as feature-rich as Abaqus, but for most day-to-day structural work, it does the job. Here's how I set up FEA simulations in SimScale.

Cloud FEA Advantages

No Local Hardware

1. No workstation: Run from any laptop with a browser
2. No software install: Web-based platform
3. Cloud HPC: Up to 32 cores per simulation
4. No license server: No FLEXlm or network license management
5. Collaboration: Share projects with team via URL

Supported Analysis Types

1. Static structural: Linear and nonlinear
2. Dynamic: Modal, harmonic, transient
3. Thermal: Steady-state and transient
4. Thermomechanical: Coupled thermal-structural
5. Fatigue: High-cycle and low-cycle fatigue

Static Structural Analysis

Setup

1. Create project > Import CAD (STEP, IGES, Parasolid)
2. Assign materials:
   • Steel: E = 200 GPa, ν = 0.3, ρ = 7850 kg/m³, σy = 250 MPa
   • Aluminum: E = 71 GPa, ν = 0.33, ρ = 2700 kg/m³, σy = 280 MPa
   • Titanium: E = 110 GPa, ν = 0.34, ρ = 4500 kg/m³, σy = 880 MPa
   • Custom: Define E, ν, ρ, yield strength
3. Assign material to each body in assembly

Mesh

1. SimScale auto-mesh:
   • Mesh type: Tetrahedral (default) or hex dominant
   • Fineness: 1-10 (5 = moderate, 8 = fine)
   • Local refinements: On faces, edges, or volumes
2. Mesh quality:
   • Aspect ratio: < 20
   • Skewness: < 0.8
   • Element quality: > 0.1
3. For stress concentrations:
   • Add face sizing on fillets, holes, notches
   • Element size: 0.5-2mm at critical regions

Boundary Conditions

1. Fixed support: Select faces or edges (all 6 DOF fixed)
2. Remote displacement: Constraint at a remote point
3. Cylindrical support: On cylindrical faces (radial, axial, tangential)
4. Symmetry: On symmetry plane (reduces model size)

Loads

1. Force: On faces, edges, or vertices (N)
2. Pressure: On faces (Pa) — normal to surface
3. Moment: On faces or edges (N·m)
4. Gravity: Body force (9.81 m/s² in specified direction)
5. Remote force: Force applied at a remote point
6. Bearing load: On cylindrical faces (radial pressure distribution)

Results

1. Equivalent stress (von Mises): σvm contour
   • Compare to yield: σvm < σy → safe
2. Displacement: Total and directional
   • Check: Within allowable deflection
3. Safety factor: SF = σy / σvm
   • Target: SF > 1.5 (static), > 2.0 (dynamic)
4. Strain: Elastic and plastic (if nonlinear)
5. Reaction forces: At supports (should balance loads)

Nonlinear Analysis

Material Nonlinearity

1. Material > Plasticity:
   • Bilinear: Yield stress + tangent modulus
   • Multilinear: Stress-strain curve (true stress vs. true strain)
2. Analysis type: Static structural, nonlinear
3. Set:
   • Nlgeom: ON (large deformation)
   • Incrementation: Automatic (auto-step) or manual
4. Results:
   • Plastic strain: Permanent deformation
   • Residual stress: After unloading
   • Load-displacement curve: Nonlinear response

Contact

1. Contacts > Define contact pairs:
   • Bonded: Surfaces glued (no relative motion)
   • Sliding: Frictionless or frictional
   • Coulomb friction: μ (friction coefficient)
2. SimScale auto-detects contacts in assemblies
3. For nonlinear contact:
   • Normal behavior: Hard contact (no penetration)
   • Tangential behavior: Penalty (Coulomb friction)

Modal Analysis

Setup

1. Analysis type: Modal analysis
2. Define supports (same as static)
3. Set number of modes: 6-20 (typical)
4. No loads required (modal is eigenvalue analysis)

Results

1. Natural frequencies: Listed in Hz
   • Mode 1: First bending
   • Mode 2: First torsional
   • Mode 3: Second bending
   • etc.
2. Mode shapes: Deformation pattern per mode
3. Effective mass: Per mode per direction
   • Sum should be > 90% of total mass
4. Participation factor: Importance of each mode

Resonance Check

1. Identify excitation frequencies:
   • Rotating equipment: f = RPM / 60
   • AC frequency: 50 or 60 Hz
   • Blade passing: f = RPM × Nblades / 60
2. Compare to natural frequencies:
   • Safe: fnat / fexc > 1.5 or < 0.67
   • Resonance risk: Within ±20% of excitation

Harmonic Analysis

Setup

1. Analysis type: Harmonic response
2. Link to modal analysis (uses mode shapes)
3. Set:
   • Frequency range: 0-200 Hz (cover modes of interest)
   • Number of intervals: 100-500
   • Damping ratio: 2-5% (steel), 5-10% (bolted joints)
4. Apply harmonic load:
   • Force: Magnitude and direction
   • Base excitation: For rotating equipment

Results

1. Frequency response: Amplitude vs. frequency
   • Peaks at resonance (natural frequencies)
2. Phase response: Phase angle vs. frequency
3. Stress at resonance: Maximum stress at resonant frequency
4. Amplification factor: Q = 1 / (2ζ) at resonance

Thermal Analysis

Steady-State Thermal

1. Analysis type: Heat transfer, steady-state
2. Materials:
   • Thermal conductivity (k): W/m·K
   • Density (ρ): kg/m³
   • Specific heat (Cp): J/kg·K
3. Boundary conditions:
   • Temperature: Fixed temperature (°C)
   • Heat flux: W/m² on surface
   • Heat flow: W on surface or volume
   • Convective heat flux: h (W/m²·K) and T_ambient
   • Radiation: Emissivity and T_ambient
4. Results:
   • Temperature distribution: Contour plot
   • Heat flux: Direction and magnitude
   • Maximum temperature: Location and value

Transient Thermal

1. Analysis type: Heat transfer, transient
2. Set:
   • Initial temperature: Uniform or from steady-state
   • End time: Total simulation time (s)
   • Time step: Based on Fourier number
3. Time-dependent boundary conditions:
   • Tabular: Time-value pairs
   • Example: Heat source turns on at t=10s, off at t=60s
4. Results:
   • Temperature vs. time: At probe points
   • Temperature at specific times: Snapshots
   • Time to steady-state: When temperature stabilizes

Thermomechanical Analysis

1. Analysis type: Thermomechanical (coupled)
2. Setup:
   • Run thermal analysis first (steady-state or transient)
   • Import temperature field as load in structural analysis
3. Material:
   • CTE (α): Coefficient of thermal expansion (×10⁻⁶/°C)
   • Reference temperature: Tref (stress-free temperature)
4. Thermal strain: εth = α × (T - Tref)
5. Results:
   • Thermal stress: From constrained thermal expansion
   • Total deformation: Mechanical + thermal
   • Combined stress: Mechanical + thermal stress
   • Safety factor: Must account for temperature-dependent properties

Fatigue Analysis

High-Cycle Fatigue

1. Analysis type: Fatigue (requires static structural result)
2. Set:
   • Fatigue theory: Stress-life (S-N) or Strain-life (ε-N)
   • Mean stress correction: Goodman, Gerber, or Soderberg
   • Loading type: Fully reversed, mean stress, or variable amplitude
3. Material:
   • S-N curve: Stress amplitude vs. cycles to failure
   • Endurance limit: σe (for steel, σe ≈ 0.5 × σUTS)
4. Results:
   • Fatigue life: N (cycles to failure)
   • Damage: D = n/N (cumulative damage)
   • Safety factor: For infinite life (N > 10⁶)

Applications

• Bracket: Cyclic loading (vibration)
• Pressure vessel: Pressure cycling
• Shaft: Rotating bending
• Welded joint: Variable amplitude loading

Cloud Computing Performance

Simulation Times

| Analysis | Mesh Size | Cores | Time | |----------|-----------|-------|------| | Static (linear) | 500K | 8 | 5-10 min | | Static (linear) | 5M | 32 | 20-40 min | | Static (nonlinear) | 1M | 16 | 30-60 min | | Modal | 1M | 16 | 10-20 min | | Thermal (steady) | 1M | 16 | 10-20 min | | Fatigue | 500K | 8 | 5-15 min |

Mesh Size Limits

| Plan | Max Nodes | Max Cores | |------|-----------|-----------| | Community | 100K | 8 | | Professional | 5M | 32 | | Enterprise | 50M+ | 96 |

Post-Processing

Visualization

1. Contour plots: Stress, displacement, temperature
2. Deformed shape: Scaled for visibility
3. Probe points: Value at specific location
4. Section cuts: Cross-section through model
5. Animations: Mode shapes, deformation

Reports

1. SimScale auto-generates report:
   • Model summary: Geometry, materials, mesh
   • Boundary conditions: Loads and supports
   • Results: Stress, displacement, safety factor
   • Figures: Contour plots
2. Export as PDF for documentation

Verification Checklist

• [ ] Material properties are correct (E, ν, ρ, yield)
• [ ] Mesh is refined at stress concentrations
• [ ] Boundary conditions prevent rigid body motion
• [ ] Loads are applied in correct direction and magnitude
• [ ] Reaction forces balance applied loads
• [ ] Maximum stress is below yield (or plasticity is modeled)
• [ ] Safety factor > 1.0 at all locations
• [ ] Deformation is within allowable limits
• [ ] Modal analysis captures 90%+ effective mass
• [ ] No resonance within ±20% of excitation frequency
• [ ] Thermal contact resistance is specified at interfaces
• [ ] Fatigue life meets design requirement

Wrapping Up

SimScale's FEA capabilities cover most of what I need day-to-day: static, modal, thermal, and fatigue. What it doesn't do is explicit dynamics — if you need crash or drop test simulation, you'll need LS-DYNA or Abaqus/Explicit. But for the majority of structural analyses that engineers run, SimScale is more than capable. I especially like the auto-generated reports — they're not perfect, but they're a good starting point for documentation. Add your own interpretation and you've got a presentable analysis package without spending hours in a post-processor.