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FEMFAT (Finite Element Method Fatigue) performs fatigue analyses in combination with all leading finite element systems considering a multitude of fatigue influences including stress gradient, mean stress and various influences from production processes.

Commonly used interfaces to multi-body-simulation programs, optimization and measurement systems are employed to ensure full and convenient integration into your CAE tool chain.

At an early stage of the design process - long before time and cost consuming tests are performed - FEMFAT provides engineers with reliable information on the fatigue life of structures. Therefore it is possible to improve critical areas and ensure weight optimization from beginning on, which results in high grade prototypes and consequently leads to fewer development loops.

The continuous practical usage of FEMFAT ensures its outstanding reliability. The FEMFAT simulation method and approach is based on decades of constant correlation between fatigue life prediction and fatigue life testing in multiple internal and external development programs. Engineering Center STEYR has incorporated the experienced out of more than 500 fatigue-related projects in analyses and testings, generating the foundation for our software engineers to develop FEMFAT to an reliable engineering tool. This made FEMFAT one of the leading fatigue analysis applications in the automotive industry and built the basis for its worldwide acceptance.

Efficiency and high quality are an absolute must for all our customers. FEMFAT accounts for many important interacting fatigue influences such as material properties, notches, mean stresses, surface roughness, temperature field, plasticity, mechanical and chemical surface treatments, component sizes, special behavior of welding seams, spot welds, self piercing rivets, multi-axial loading and much more.

FEMFAT results can be displayed graphically using either the FE post-processors or the FEMFAT VISUALIZER module. The result types include damage, safety factors of endurance or static loads as well as stresses, ratio and multiaxiality.

An output record file shows all relevant material data, analysis parameters and stress tensors for highly loaded nodes including detailed fatigue results.

Methods and verification

The methods used in FEMFAT are based on the latest scientific findings of the German FKM-guideline, and the work of Hück/Thrainer/Schütz (synthetic S/N-curves), on the local stress strain conception (TU-Darmstadt), on the R1MS-conception for assessment of welding seams and on ECS-proprietary methods for spot joints. Supplementary to the statements made above, methods applicable to FEM were developed, such as the calculation of notch influence with regard to the relative stress gradient or consideration of the interaction of different stress-tensors by using the method of the "critical cutting plane".

These entire hypotheses have been checked by comparing numerous test series with fatigue analysis results and have been verified during many years of practical use.


FEMFAT is a comprehensive tool that provides quick and reliable answers concerning the design release of components.
FEMFAT combines know how from the special fields Finite Element Method, characterization of material properties and fatigue testing. Its graphic user interface guides the user step by step. Very few modifications of settings are required to carry out a fatigue analysis.