Spring Coil Test Machine (SCTM)

The Development and Quality Monitoring of resilient, highly stressed automotive components such as springs, requires testing that represents actual vehicle conditions as accurately as possible.

The influences relevant to fatigue strength must therefore be known and the effects therefore determined with the testing of adequate specimens.

The IABG Spring Coil Test Machine allows the time- and cost-saving determination of the fatigue strength of individual spring coils under corrosion. In this way, it is possible to perform comparative tests to determine the influence of specific factors on the fatigue strength of the test samples.

Advantages compared to other existing test machines

  • Energy efficient due to the application of resonance principals
  • High test frequencies
  • Under corrosion lower test frequencies are also possible in the slow drive function
  • Short set up and test specimen exchange
  • Reliable and low maintenance
  • Testing under temperature and corrosion

Test possibilities

Due to the special geometry of the test specimen, in this test it is possible to load the spring wire approximately 40% more than in a test with a complete spring. This allows for a greater variation of the mean load and a very time efficient test procedure.

Experimental examples:

  • „„Examination of the surface protection, the influence of pre-corrosion and corrosion during a test under realistic conditions
  • „„Examination of the influence of the test frequency on the fatigue life under corrosion
  • „„Verification of the influence of the material, the heat treatments, the shoot-peening process, the surface layer quality and the surface protection
  • „„Analysis of the influence of the mean load (vehicle load)
  • „„S/N Curves (Wöhler lines)
  • „„Scatter and distribution in the finite-life fatigue strength area and fatigue limit areas
  • „„Analysis of the fatigue life predictions (damage accumulation) under collective load

Technical data

  • Test specimens: two spring coils taken from cylindrical passenger vehicle springs
  • Mounting and loading in test machine:
    between load tips
  • Spring wire diameter: d < 22 mm
  • Spring diameter: Dm = 40 to 320 mm
  • Test frequency:
    Slow drive f = 0,2 to 1,5 Hz
    Fast drive f = 8 to 40 Hz
  • Environmental conditions: normal laboratory atmosphere or salt water spray
  • Weight / Measurement of machine (without switching cabinet): 1000 kg, L = 1200 mm, W = 1100 mm, H = 1600 mm
  • Power consumption: < 1 kW