For clarification of issues referring to static and/or fatigue strength of components we support you by inquiries and ap-plication of Swiss and/or European standards. We provide ad-vice regarding strain measurements, performing static and/or fatigue tests as well as design or manufacturing actions to avoid fatigue cracks and/or to increase the lifetime of components.

The design of components and its mathematical or experi-mental strength analysis requires knowledge of affecting service loads. Considering operating time, service modes and conditions, we also support you in the definition of relevant strain components and the definition of measuring points as well as the evaluation of measuring signals. For data acquisition, there are battery-supplied, mobile devices available (up to 40 channels with sampling frequencies up to 2'400 Hz) for long and short-term measurements in the field as well as in the laboratory. We evaluate recorded load histories with re-spect to fatigue relevant, statistical properties and preprocess those for service load simulations on fatigue test facilities if required

For experimental strength verifications, we load your compo-nents or entire structures statically or oscillating. If required, we monitor loads, strain and deformation up to indication of unacceptable deformations or cracks or until complete failure respectively. At the same time, we realize tailored test setups adjusted to test components with regard to customer specific requirements. Two universal floor slabs (platen area: 4 x 8 m and 4.5 x 8 m respectively, heights: 10 m and 4 m respectively) and modular construction elements are available for such set-ups. Static and oscillating loads include tensile and compres-sion forces (up to 100 kN), flexural loads (3-point, 4-point bending) as well as torsional loads and its combinations.

For the mechanical characterization of metallic materials (steel, aluminum, magnesium, copper etc.), we give advice regarding sample geometry, type of loading and test strategies with re-gard to your requirements. We therefore define test series (stress or strain controlled) for the determination of SN-curves in the range of limited lifetime and/or stair case tests to de-termine the material fatigue strength with specified probability of survival. Tests on material samples may be carried out at temperatures between 50°C and 450°C.

Bainitic steels are used increasingly in the automotive industry. As for a reliable design of components, the strength capacity hasn't yet been fully exploited, improved steels, which show the so-called TRIP-effect (TRansformation Induced Plas-ticity), have been developed.

The investigation of mechanical fatigue properties in the course of material development processes by using standard fatigue tests is time consuming, costly and therefore, not economical. Based on modern models, a shortened, experimental method has been introduced and verified in the frame of a re-search and development project. This method enables the es-timation of a complete SN-curve (limited life time and fatigue strength) carrying out three to five fatigue tests.

Contact: Dipl. Ing. ETH Ch. Affolter, Dipl. Ing. FH A. Stutz

The finite element method (FEM) is a versatile tool for stress and strength calculations, design optimisation (‘generative’, or by means of parameter optimisation) or process simulations.

In addition to the FEM stress analysis, an early estimation of service life contributes significantly to cost savings in the development and design of components and structures under repetitive loads. We support you both in the modelling of your components to determine relevant stress components, and in the application of the latest FKM guideline for the computational verification of static strength, fatigue strength or fatigue endurance limit.