Low-Load Fatigue Tester (5-20kN)

Low-Load Fatigue Tester (5-20kN)

Parent Product
Resonant Fatigue Testing Machines
Mikrotron Resonant Fatigue Testing Machine

Mikrotron Resonant Fatigue Testing Machine - Low-Load Fatigue Tester

Compact version, for low load range 5-20 kN

The MIKROTRON is the smaller and more compact execution of the TESTRONIC for loads up to 5kN resp. up to 20kN and – if necessary – for higher dynamic stroke values.

The main feature of this construction is the big stroke of the oscillating mass leading to a particularly low total weight for a resonant testing machine (only approx. 30% in comparison with other testing systems in the market). Thanks to the T-slotted machine table the range of applications is extended to the more and more required testing of components.

Due to the control unit being located in the load frame the MIKROTRON is a very compact and thus space-saving testing solution. The operating frequency ranges from 40Hz to 250Hz depending on specimen stiffness and activated masses of the oscillating system (adjustable in 4 resp. 5 steps).

 

Applications

Resonant Fatigue Tester Machines are very often used for fatigue tests (S/N - curves) or in the fracture mechanics for precracking and crack propagation tests. This principle has many advantages compared to servo-hydraulic machines.

All types of tests with a high number of load cycles are beneficial applications for resonant testing machines because of the high testing frequency, and as a result very short testing time as well as very low power consumption.

The additional advantage in comparison to servo-hydraulic systems with its actuators, valves and pumps is that maintenance is not required due to the wear-resisting construction.


Clamping device Hydrogrip 20kN with welded specimen


Automated specimen supply


Torsion device


Alternating bending in 4-point arrangement


Clamping device for fracture mechanics specimens


Special device for alternating bending on welded specimen

Features/Advantages
  • Utmost measurement and control accuracy (class 0.5% for static and for dynamic load)
  • Short test duration due to high testing frequencies (40Hz– 250Hz)
  • Universal test applications due to the high-performance dynamic drive RUMUL MIKROTRON and the big test space with T-slotted machine table
  • Easy, safe and ergonomic operation
  • Marginal running costs (1%–2% only in comparison to servo-hydraulic test systems!)
  • No maintenance
  • No additional equipment such as power pack, cooling etc. required
  • Minor footprint due to the integration of controller in the load frame
  • Top-quality made in Switzerland
Theory/Method

Powerful and universal, energy-saving and fast

Static Drive

The static load is applied by a ball spindle (10) with a preloaded double-nut which is driven by a low-backlash gearbox and a servomotor. Thanks to this preloaded double-nut the static load can be adjusted during the dynamic operation in the complete range of the nominal load (100% compression up to 100% tension).

Dynamic Part

The dynamic part mainly consists of the oscillating mass m1 (4), the counter mass m0 (8), the elasticity c (6) of the specimen and all other elasticities and masses within the dynamic load flow. These parts form the oscillating system which is controlled and excited by the MIKROTRON drive in its resonant frequency. The short and optimized load flow between the two masses assures a good transfer of the load and a high amplification of the energy fed in.

Load Measurement

The load is measured by means of load cells which have proved their reliability over many years. Besides their unlimited fatigue life, their features are very high stiffness to tensile, compressive, bending, shearing and torsion loads. The load cells may either be fixed on the T-slotted table or on the upper crosshead preferably when testing components. The load cells are fitted with a built-in acceleration transducer for the compensation of the inertia forces resulting from oscillating gripping devices.

MIKROTRON Design and Resonance Principle

Legend

  1. Magnet for dynamic drive
  2. Cross head
  3. Preload springs for static load
  4. Oscillating mass m1
  5. Columns
  6. ColumnsSpecimen / component c
  7. Load cell
  8. Counter mass m0 built as T-slotted table
  9. Spindle drive with servo motor
  10. Movable lower cross head
  11. Premium ground ball screw spindle
Technical Specification
Version 5 or 20 kN
Max. peak value of load 5 or 20 kN
Max. static load 5 or 20 kN
Max. dynamic load +/- 2.5 or +/- 10 kN
Max. stroke 4 mm
Range of operating frequency 40 – 250 Hz *
(depending on specimen adjustable in 4, alternatively in 5 steps)  
Approx. Weight 600 kg *
Power requirements 230V / 10 A