Test bench for determining the fatigue strength of round bars and tubes as used in the production of suspension springs and stabiliser bars for automobiles.
Technical specification
- Test items: machined or unmachined cylindrical bars or tubes (also for stepped shafts).
- Bar/tube diameter: d = 10 to 30 mm
- Bar/tube length: L = 60 x d + 140 mm (or special lengths)
- Test frequency: f = 5 to 50 Hz (variable)
- Power consumption: < 1 kW
- Properties: no outgoing vibrations, very quiet
- Weight: approx. 1000 kg
- Dimensions: L = 2600 mm, W = 1000 mm, H = 1500 mm
- Loading: load input via crowned, non-wearing plastic rings
- Load (stress) and strain measurement
Advantages compared with existing test machines
- No clamping of the round bars necessary (fits all diameters in specified range).
- Surface under tension stress is untouched.
- Large and therefore representative material volume.
- Short set-up and changeover times (approx. 5 min.).
Purpose of the rotating bending tests
- Comparison of fatigue strength before machining of the raw material into the end product.
- Material optimisation (e.g. type of material, heat treatment, shot blasting parameters, reduction of variance etc.).
- Determination of fractures, inclusions and similar flaws in materials.
- Assessment of surface quality.
- Quality control.
Typical results
- Fatigue strength in range.
- Fatigue endurance limit.
- Dispersion along the Wöhler line.
- Fractography of shot-blasted rods with a diameter of 22 mm made of spring steel.
Typical users
- Wire manufacturers for the production of springs and stabiliser bars
- Manufacturers of springs and stabiliser bars
- Manufacturers of high-grade spring steel
- Generally all manufacturers requiring steel of high purity
Based on the same technical principle, we have developed a rotating bending test bench for diameters of up to d = 60.0 mm. |
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