Static and nonlinear FEA – plastics and metals

What we do

We predict deformation and failure of plastics and metals under real boundary conditions using static and nonlinear FEA. From snap-fits and film hinges (living hinges) to brackets, welds and adhesive joints, we model large deformations, contact, plasticity, hyperelasticity, creep and buckling – and then translate the results into clear design changes that your suppliers can actually manufacture.

Target outcomes

  • Verified safety factors and deformation limits under realistic load and boundary conditions.
  • Accurate permanent set and strain hot-spots, not just linear stress plots.
  • Robust snap-fits and hinges with target values for lifetime (opening and closing cycles) and assembly forces.
  • Weight and cost reduction while still meeting stiffness and strength requirements.

Services

  • Linear to nonlinear upgrade – start from existing linear checks, then add geometric, material and contact nonlinearity where it actually changes the answer.
  • Material modelling and calibration – true stress–strain curves, plasticity (bi- or multilinear, isotropic or kinematic), hyperelasticity (Neo-Hooke, Mooney–Rivlin, Ogden), viscoelasticity (Prony) and creep behaviour.
  • Contact and assembly – frictional contact pairs, bolt pre-tension, press fits and interference, snap engagement, and adhesive layers using cohesive-zone models.
  • Buckling – linear eigenvalue buckling plus nonlinear arc-length (Riks) analysis to capture post-buckling behaviour.
  • Rate and temperature effects – strain-rate sensitive plastics and temperature-dependent moduli and yield strengths, including thermo-mechanical coupling where required.
  • Joints and welding – bolted joints with pre-load and relaxation, modelling of fillet and spot welds, bonded joints with failure envelopes.
  • Design optimisation – thickness and rib tuning, bead patterns, local radii and blends, and material changes.
  • Test planning and correlation – test fixtures, load cases, measurement concept (strain gauges, DIC) and acceptance criteria.

Your deliverables

  • Engineering report (PDF) – scope and assumptions, meshes, material cards, load cases and boundary conditions, results with hot-spot annotations, risk ranking and concrete design recommendations.
  • Solver decks and post-processing files – ready-to-run models for Ansys, Abaqus or LS-DYNA with load steps, contact definitions and post-processing templates.
  • Material cards – calibrated parameters for plastics and metals (with EN / DE data sources noted), including temperature and rate tables where applicable.
  • CAD mark-ups – proposed changes to ribs, radii, thicknesses, snap geometry and joint details (screws, adhesive).
  • Validation plan – suggested tests, sensor layout and a correlation matrix between simulation and lab.
  • Handover session – 45 to 90 minutes live walkthrough and Q&A with your team.

Technology stack

  • Solvers: Ansys Mechanical, Abaqus Standard / Explicit, LS-DYNA.
  • Pre / post: Workbench, HyperMesh / ANSA, Meta / Post plus Python-based notebooks.
  • Analyses: linear static, geometric nonlinearity, plasticity, hyper- and viscoelasticity, creep, contact and buckling (eigenvalue and Riks).
  • Materials: ABS, PC, PA, PP, POM, elastomers and TPU, glass-filled plastics, steels, aluminium, magnesium and titanium, with optional orthotropy when orientation data is available.
  • Features: snap-fits and living hinges, inserts and domes, welds, adhesive joints and threaded connections.

Engagement flow

  • Discovery (30 minutes) – goals, boundary conditions, load cases and acceptance metrics.
  • Data and setup – CAD and materials, joints and connections, mesh and contact strategy, plan for material calibration.
  • Simulation – baseline linear checks, then nonlinear runs and sensitivity / what-if studies; buckling analysis where relevant.
  • Recommendations – prioritised design actions with the expected impact on your KPIs.
  • Validation – optional lab correlation and final report / model update.

What we need from you

  • CAD data (STEP / Parasolid) and assembly details (screws, adhesives, inserts, welds).
  • Material datasheets or test curves (tension / compression, DMTA for elastomers where available).
  • Definitions of loads and boundary conditions, load spectra and the relevant temperature range.
  • Success criteria: required safety factors, maximum allowable deformation and permanent set, target cycles to failure, and any customer or norm-based limits.

Packages

  • Nonlinear assessment – upgrade an existing linear analysis to include the relevant nonlinearities, calibrated materials and a concise risk list.
  • Simulation sprint – full nonlinear model (contact, plasticity, living hinges), buckling as needed, plus report and CAD mark-ups.
  • Correlation and optimisation – test plan, simulation-to-lab update and weight / cost optimisation.

Example use cases

  • Snap lid – reduce assembly force, protect notch roots and predict permanent set after 100 opening / closing cycles.
  • Metal bracket – capture plastic hinge behaviour and raise safety factor via local radii and beads.
  • Adhesive joint – cohesive-zone modelling to size adhesive width and fillet, with peel and shear envelopes.
  • Thin cover – nonlinear Riks buckling to avoid oil-canning under pressure or handling.

FAQ

Do you create material cards if we have no test data?
Yes. We can derive material cards from reliable datasheets and literature. Assumptions are clearly documented and we add sensitivity bands. Best accuracy comes from your own test curves.

Can you model insert-moulding and creep in plastics?
Yes. We model insert interfaces and long-term creep and relaxation in plastics, including temperature and rate effects where needed.

How do you avoid overly stiff contact behaviour?
By choosing appropriate contact formulations and penalty settings, and by refining meshes where necessary, then verifying with convergence checks.

Do we get the FEA files?
Yes. You receive the full solver decks and post-processing templates.

Do you support anisotropy and fibre orientation?
Where orientation data is available, we can include orthotropic behaviour and consider reductions at weld lines.

Contact us