équipement de laboratoire d'essai des matériaux

Standards EN 12697-24, 12697-26, 13108-20, AASHTO T321
The Servo-Pneumatic Four Point Bending Apparatus comprises of a pneumatically powered loading system, a beam cradle, an optional environmental chamber, IMACS Integrated Multi-Axis Control System and Windows application software.
The beam cradle has been designed to subject an asphalt beam specimen to 4 point bending with backlash free rotation and horizontal translation of all load and reaction points.

SPECIFICATIONS
Features
Digital servo-controlled hydraulic actuator provides accurate control of loading wave shape
Innovative “floating straight-edge” on-specimen transducer eliminates errors due to frame compliance
Backlash free rotation and translation on all load and reaction points
Sinusoidal or have sine controlled strain or controlled stress loading
Controlled force, motorized specimen clamping
Non-linear regression data fitting ensures reliable determination of phase and modulus
Cost effective solution for high volume testing

Dimensions and weight
Apparatus: 460(l) x 230(w) x 600(h)mm / 35kg
IMACS: 450(l) x 360(w) x 270(h)mm / 11kg

Air Accumulator: 450(l) x 470(w) x 330(h)mm / 9.5kg
Loading Frequency up to 60Hz*
Load Capacity up to 5kN dynamic
Actuator Stroke 10mm
Specimen Size 70 max(h) x 85 max(w) x 380 min(l)mm
Air Supply Clean, dry air at 800-900kPa, 5l/s min
Control & Data Acquisition, see IMACS specifications
*Load limitations apply at higher frequencies

The specimen is laterally positioned by hand using etched lines as a visual guide for 2 specimen sizes, nominally 50 and 63.5 mm in width.
Vertical clamping of the specimen is achieved by servo-motor driven ball screws which are operated continuously during the test to take up the compliance of the specimen at the clamping surfaces and the clamping force is controlled via the IMACS by regulating the motor current.
The pneumatic system uses a bottom loading actuator system with a high performance servo valve, with PID closed-loop control and a run time adaptive control algorithm that adjusts the command signal during the running of a test.
The test control system is computer based, using sensors on the machine for feedback (load and strain) signals.
The user friendly PC software is menu-driven. The system gathers the dynamic data from the specimen under test, then displays plots appropriate to each test type and function mode, in real time on the PC. Optional non-linear regression data fitting ensures reliable determination of phase and modulus.
The software automatically saves test information in binary file format, allowing data files to be generated for importing into a spreadsheet package, or review of previously-run tests through the graphics screens of the system. Binary files may also be emailed for diagnostic purposes.

Complies with the following standards:
EN12697-24 Annex D*
EN12697-26 Annex B*
prEN13108-20 Annex D*
AASHTO T321 (formerly TP8)
AST 03 (AUSTROADS)