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 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.
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.
Features
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
Solid state control and measurement electronics for Amsler Vibrophore ®
Load control, single DPM version QT1000
Introduction
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.
Features
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.
Counter
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.
Features:
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.
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
