FEM simulation: predicting loads virtually

FEM (Finite Element Method) simulation allows stresses to be predicted virtually – before prototypes are built.
Engineers can identify stresses, deformations, natural frequencies and safety margins at an early stage, reduce the number of iterations and make well-founded decisions.

Whether it’s lightweight construction, service life verification, thermal-mechanical coupling or a structured component analysis, these approaches shorten time-to-market, reduce costs and improve product quality.

Today’s products are lighter, more complex and more functional. Materials are becoming more demanding, and operating conditions more variable. Traditional trial-and-error cycles using physical prototypes consume time and budget.

FEM simulation bridges this gap: it makes assumptions explicit, highlights stresses within the component, assesses stiffness and strength, and reveals critical details.

The result: more variants tested within a shorter timeframe and verified decisions even before the first investment in tooling.

A structural analysis of a component answers four key questions:

1. Is the geometry structurally sound?
   Stresses remain below permissible limits; deformations do not impair function or appearance.
2. How robust is the design?
   Tolerances, manufacturing variations and load combinations are covered by means of sensitivity analyses and ‘what-if’ scenarios.
3. How long will it last?
   Service life under time-dependent loads (low- and high-cycle fatigue), vibrations and temperature cycles.
4. Where can optimisation be applied?
   Targeted material redistribution, adjustment of ribs and webs, rounding of edges, and variation of wall thicknesses as required.

The finite element method translates these questions into a numerical model comprising elements, boundary conditions and material constitutive laws. This allows not only static cases to be modelled, but also dynamics, thermomechanics and non-linearities (contact, large deformations/strains and non-linear material behaviour).

• Network convergence rather than gut feeling: systematically vary the element size until the results stabilise.
• Model contact correctly: Set friction coefficients and stiffness transitions to reflect reality.
• Identify singularities: Correctly interpret theoretical peaks at sharp geometries.
• Model materials realistically: elastic-plastic, temperature-dependent, work-hardening – rather than purely linear.
• Check boundary conditions: Question degrees of freedom and support conditions; overly rigid constraints distort loads.
• Review results as a team: Mechanics, manufacturing and quality teams should review the results together – technical plausibility trumps perfect colour plots.

Once the component analysis has identified any hotspots, targeted optimisation begins:

• Topology & shape: reposition ribs, increase fillet radii, implement a design optimised for load paths.
• Weight vs. stiffness: sandwich structures, ribs, local reinforcements instead of uniform wall thicknesses.
• Service life: Notch factor, mean stress, amplitude of vibration – take strength design concepts (e.g. FKM guideline) into account.

Durability is often a decisive factor when it comes to warranties, product recalls and reputation. FEM simulation provides local stress distributions; combined with material properties and Wöhler curves, this enables a service life analysis to be carried out.

Key factors include the influence of intermediate stress, notch sensitivity, surface finish, temperature and correct load distributions. For varying operating profiles, a block programme or a time-series-based analysis is recommended. The aim: reliable designs with minimal material usage.

• First-pass yield: Initial approval without rework
• Iterations until approval: digital vs. physical
• Prototype reduction: quantity & costs
• Weight reduction: whilst maintaining a constant safety factor
• Time-to-Decision: Time to a reliable recommendation
• Field returns / million units: Post-SOP
• MTBF: Mean Time Between Failures for lifespan-related issues

These key performance indicators link FEM simulation directly to business objectives: quality, speed and cost.

An aluminium housing subjected to compressive stress showed localised stress exceedances at a flange during the initial component analysis. By rounding the edges, repositioning the ribs and making a moderate adjustment to the wall thickness, the local stress was reduced to below the permissible value, whilst the deformation at the sealing line was halved. At the same time, the service life assessment revealed a significant margin of safety against cyclic loading. Result: weight reduced by 8 per cent, safety factor increased by 20 per cent, a compact, manufacturable design – without the need for an additional prototype.

• Design Engineering: Functional requirements, change management, manufacturability.
• Simulation Team: Modelling, solution, interpretation of results.
• Testing & Validation: Reference cases, measurement calibration, approvals.
• Quality & Compliance: Standards, documentation, audit readiness.
• Product Management: Target parameters, trade-offs, business decisions.

This ensures that FEM simulation does not operate in isolation, but is embedded within the organisation as an end-to-end decision-making process.

Those who can predict stresses virtually can make decisions earlier, save on prototypes, reduce risk and enhance customer value.The finite element method provides the necessary depth – from linear estimates to complex, coupled analyses. With accurate component analysis, transparent boundary conditions and rigorous validation, a robust development standard is established – one that is efficient, auditable and scalable.