Last updated: 2026-09-10 6 min read

Validation objective

These cases verify that Indux Mechanical solves its governing equations correctly by comparing the numerical results with published closed-form solutions. Because no experimental uncertainty is involved, they isolate the numerical formulation and implementation. Mesh refinement is also checked where appropriate to confirm that the error decreases at the theoretically expected rate.

Validation matrix

The suite contains eight cases across four physics areas: four structural, two heat-transfer, one thermal-stress, and one coupled thermo-mechanical problem.

  • Tools: Gmsh 4.12.2 for mesh generation, SU2 mesh format, Indux Mechanical built with MSVC/VS2022, and MKL PARDISO/FGMRES linear solvers
  • Acceptance criteria: relative error ε<1%|\varepsilon| < 1\% for smooth, nonsingular quantities and an observed mesh-convergence order pobs2p_{obs}\approx2
  • Quantity-selection rule: isolated maxima at boundary-condition corners, constrained edges, and mesh-star centers are not used as primary evidence; interior values, averages, and profiles are preferred
  • Overall result: 8/8 PASS

Detailed equations, boundary conditions, acceptance quantities, and results are documented separately.

  1. Tension Bar — uniaxial tension
  2. Lamé Cylinder — internally pressurized thick cylinder
  3. Plate with Hole — elastic stress concentration
  4. Rotating Disk — centrifugal loading
  5. Fin Convection — convective heat transfer
  6. 1D Heat Conduction — steady conduction
  7. Thermal Stress Bar — restrained thermal expansion
  8. Coupled Thermal Stress — one-way thermal-to-structural coupling

Results summary

CaseProblemVerification quantityTheoryFEMError
1Tension BarMean von Mises stress σ\sigma1.000e6 Pa9.95e5 Pa−0.50%
1Tension BarAxial displacement δx\delta_x5.00e-7 m4.98e-7 m−0.40%
2Lamé CylinderInner radial displacement ur(a)u_r(a)4.767e-7 m4.755e-7 m−0.25%
3Plate with HoleStress concentration factor KtK_t3.002.99−0.3%
4Rotating DiskCenter von Mises stress σvM\sigma_{vM}3.238e7 Pa3.236e7 Pa<0.3%
5Fin ConvectionTip temperature TtipT_{tip}331.03 K331.03 K~0%
61D ConductionT(x=0.05)T(x=0.05)350 K350.00 K0.00%
7Thermal Stress Barvon Mises stress2.4×10⁸ Pa2.4×10⁸ Pa0.00%
8Coupled Thermal Stressvon Mises stress2.4×10⁸ Pa2.4×10⁸ Pa0.00%

All eight cases satisfy the acceptance criteria for their designated primary quantities. Comparisons with experimental measurements are planned as a separate validation stage; these closed-form cases specifically address code and solution verification.