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Test machines

Torsion machines
Component test
Resonant HCF
Steering column
Second user

Test ancillaries

Data acquisition
Specimen fixing


Gas flow


Bespoke machines


Strain gauge
Electronic assembly


I/O cards

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Resonant test machines

Resonant test machines are ideal where a large number of cycles is required, with typical test frequencies in the range 80 – 300Hz.

The main application is HCF (high cycle fatigue) in the following areas
  • materials testing – research into material properties
  • bolt and fastener testing – often in the aerospace industry
  • re-enforcing bar testing – in the steel/construction industry
Click the links for more information

Amsler Vibrophore® Frames - Supply and upgrade

Si-Plan can upgrade customers' test machines to the latest standards.

Si-Plan usually has second-hand refurbished machines available with new digital controller or second-hand analogue controller. These machines can be delivered, installed and calibrated to UKAS and ASTM standards.

Mechanical and electrical spare parts can also be supplied for most machines.


Si-Plan resonant test machine frames

Si-Plan also offers new resonant testing machines of our own design and manufacture. Typical sizes are 20kN, 100kN, 200kN, 400kN and 600kN frames. The 400kN machine illustrated below is configured for testing rebar. The frame dimensions are 1259mm x 2500mm x 5000mm tall.

Grip and collet systems for rebar, bolt and materials tests are offered as accessories and specific fixtures enable torsion and bending tests. Furnace and environmental chambers further widen the testing scope of the resonant machine.


Digital controller for resonant test machine

Si-Plan Electronics Research's digital Vibrophore controller and data acquisition facility offers a computer interface control for resonant machines, both new frames and second-user. The 32 bit servo controller, based on a 400MHz XScale™ Intel processor, has 16 bit analogue inputs for data acquisition.

  • Free-standing PC as user interface
  • Remote pendant for crosshead adjustment
  • Electronics cabinet housing
    • Twin 400W power amplifier
    • Digital servo-controller
    • Crosshead motor amplifier
    • DC Power unit
    • Transducer signal conditioning
The computer interface window (below) replicates the options for setting parameters available on Si-Plan's solid state control and measurement electronics.
  • Cycles counter Set cycles; display of cycles done and cycles remaining display
  • Crosshead Set mean load. Select auto or manual control. Select manual up or manual down
  • Dynamic control Set dynamic demand. Select Run or Stop
  • Load cell Select load cell: 20kN; 50kN; 100kN; 150kN
  • DPMs display figures indicating the state of the test: Frequency, Mean, Compression; Range; Tension
The real-time rolling screen display (below) gives a graphical presentation of the test.
  • Data logging for every cycle and/or every nth cycle and/or every 2n cycles to a CSV file which can be imported into spreadsheet programmes.
  • Data fields include Mean, Range, Peak tensile load and Peak compressive load.

Analogue controller for resonant test machines

Solid state control and measurement electronics for Amsler Vibrophore ®
Load control, single DPM version QT1000
Si-Plan Electronics Research Ltd has been building and fitting control electronics to update Amsler Vibrophore frames® for over 25 years. The present systems offer solid state computer compatible control and measurement electronics with load signal conditioning and single DPM display.

  • Manual operation
  • Computer controlled operation (optional extra)
  • Control accuracy typically 1% of full scale.
  • Setting of these parameters by front panel control with digital readouts:
    Dynamic load
    Static load (tension or compression; automatic or manual control)
    Number of fatigue cycles (from 100 to 100 million)
    Trip zones
  • 110 volt (15 amp) and 230 volt (8 amp) versions available.
  • A free-standing 19" cabinet houses the main system elements:
  • Instrumentation rack
  • Twin 400W power amplifier
  • Crosshead motor amplifier
  • Power unit

  • The instrumentation rack consists of 8 modules:
    Power Supply Module
    The power supply is 55W ±14volt and 5 volt output for the instrumentation electronics.
    Select the number of fatigue cycles to which the specimen is to be subjected. Any number of cycles from 100 to 100 million may be pre-set by means of the push buttons on the front of the counter and the decade switches below.
    Crosshead Motor Control Module
    Controls the static load applied to the test specimen by either manual or automatic control. In manual mode the operator depresses either the UP or DOWN button and observes the static load being applied to the test piece as indicated on the DPM module. In the automatic mode the operator sets the required load on the control marked SET LOAD, selects either TENSION or COMPRESSION using the selector switch next to the SET LOAD control and then depresses the AUTO ON button. The AUTO ON, UP and DOWN buttons are illuminated when that parameter is being used. In the case of auto operation the UP and DOWN lights will illuminate only when the motor is being used so that when the set point is achieved both will be extinguished. A remote manual control is also supplied, connected to the control electronics via a 4m cable.
    DPM Module
    A 4.5 (19999 fsr) digital panel meter (DPM) to indicate the load and test frequency applied to the test specimen. Select the parameter to be displayed on the DPM by depressing the appropriate buttons.
  • LOAD is displayed in newtons.
  • MEAN displays the static load being experienced by the test specimen.
  • RANGE displays dynamic load.
  • TENS (tensile load) displays the most tensile load being experienced by the specimen in engineering units.
  • COMP (compression) displays the least tensile load being experienced by the specimen.
  • FREQ displays the dynamic load frequency.
    Control Module
    Used to set the level of dynamic load -peak to peak load - at which the operator requires the specimen to be tested.. The dynamic load is set independently of the static load
  • Press RUN to start the machine.
  • Press STOP to stop the machine. The test will also be stopped when the pre-set count value on the counter is reached.
    Auto Zero Module
    Stores the machine settings at start up (immediately the RUN button is released) so that the trip module is automatically referenced to the required static and dynamic loads.
    Trip module
    Compares the current dynamic and static load with the initial values stored by the autozero module. Stops the machine if the current values vary from the set value by more the the amount set with the TRIP ZONE control.
    Load Cell Amplifier Module with multiple channel auto select
    This module contains the strain gauge amplifier, bridge supply and associated range selection to scale the output voltage of a range of load cells to the correct level required by the control system. The load cells will be typically 20-200KN. This module also contains precision shunt calibration resistors. The control cabinet also houses:
    Twin 400W Power Amplifier
    This amplifier is connected to a matching transformer which is in turn connected to the AC excitation coil of the electromagnet in the load frame. The two 400W amplifiers are precisely matched and are working in parallel to provide 1400W peak power in the exciter coil when large or power absorbing specimens are being tested.
    Crosshead Motor Amplifier
    The high current drive amplifier for the crosshead motor, providing precise control of the static load applied to the specimen when the auto button is depressed.
    Power Unit
    This unit contains DC power supplies for the control coil of the electromagnet in the load frame and the power amplifier matching transformer.
  • High Medium Low power settings
  • Power amplifier current meter
  • Power amplifier health indication
  • Machine On/OFF switch
    Optional extras
  • Crosshead Motor Conversion Kit: strongly recommended to ensure significantly improved system performance (mean load control) compared with the original AC motor system.
  • Computer control package: Pentium system with Si-Plan Servo controller and data acquisition unit; LabWindows software.

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    Resonant test machines - background information

    Since the early 1970s Si-Plan has manufactured replacement controllers for Vibrophore Resonant Test Machines. The first systems replaced the original valve-based controllers supplied with the Vibrophores. They provided solid state analogue control, bringing better control of test loads and much improved reliability and ease of use. Many of the early Si-Plan Vibrophore controllers are still in daily operation.

    The analogue controller was continually developed until 2004, when it was superseded by the digital controller, with computer user interface and data logger. The user screen is illustrated below. Where required, customer specific software and user interface can be offered.

    Resonant machines come in a number of forms and common names are Si-Plan®, Amsler®, RUMUL®, Zwick® and Instron®.

    Resonant test machines are ideal where a large number of cycles is required, with typical test frequencies in the range 80 – 300Hz.

    Resonant machines are also very energy efficient with power requirements on a test of 10kN – 100kN at 120Hz, for example, in the order of 600 watts. Contrast this with a servo hydraulic machine which would test at around 30Hz and require in excess of 20 kilowatts.

    The main application is HCF (high cycle fatigue) in the following areas
    • materials testing – research into material properties
    • bolt and fastener testing – often in the aerospace industry
    • re-enforcing bar testing – in the steel/construction industry

    Updated 6 July 2012

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    Si-Plan Electronics Research Ltd, Avenue Farm Industrial Estate,
    Birmingham Road, Stratford-upon-Avon, CV37 0HR, UK
    Tel International: +44 1789 205849 | Tel UK: 01789 205849
    Fax International: +44 1789 415550 | Fax UK: 01789 415550

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