The Wille Geotechnik Resonant Column is a highquality apparatus for measuring the low-shearStrain (less than 0.001%) or elastic modulus anddamping properties of materials (e.g. wide varietyof soils, rocks, Asphalt, etc) for solid- or hollowcylindrical samples under confined condition.
It works based on the theory of wave propagationand used to vibrate the top of the soil specimenThe device can work under two differentboundary conditions, so called free-free and fixfree conditions, which depends desiredstrain that operator wants to start RC experiment.
Users can control the system with a dedicatedsoftware installed on user’s computer (Windows,Linux or Mac operating system.).The software isuser friendly and operator can easily control all ofcomponents of system. The procedure of runningthe test is simplifies by the software and muchkind of tests can apply by this software.
The device can run the tests on soils, includingmixtures of clays, silts and sands, and othermaterials (excluding Rock), and also possible todo test on organic soils (soft soil).
General Description
The Wille resonant column is equipped for isotropic and as an option for anisotropic tests. Also this apparatuscan be upgraded to perform experiments in unsaturated condition. Several other upgrading options are availableon client’s request.
Device Geography
① Pressure cell
② Lifting frame for easy cell top removal
③ Heavy base plate to reduce vibration
④ Resonant column Driving /measuring unit
⑤ Anisotropic test(optional) / Axial loading unit
⑥ Inner cell
⑦ Automatic Pressure controlling system
⑧ Automatic Volume Measuring device
⑨ Data acquisition And Power Amplifier Unit
⑩ Calibration rods
Resonant Column Driving /Measuring Unit (Excitation Unit)
The driving system is designed andmanufactured with a really low weight andcompact size to avoid even small stressanisotropy which results from the weightof the excitation part.
The driving system consists of two lightmini-actuators which decrease the extraweight on the top of the sample significantlyin comparison with the existing devices inmarket.
This high precision torsional drive systemused to vibrate the top of the confinedsolid or hollow cylindrical soil specimen toget the resonant frequency of specimen, frequency of 3000 Hz.
Anisotropic Test/ Axial Loading Unit (Optional)
The main device during construction can beupgraded to Anisotropic test with Automaticsoftware controlled loading system e.g. pneumaticor electromechanical actuator to apply load fromtop of the sample with high capability for verticaldeformation up to 8 kN.
With this option, the user does not need to haveanother set up for anisotropic tests.
Triaxial Pressure Cell
Advanced special high quality Transparentstainless steel triaxial gaseous cells are availablefor samples with diameters between 38 to 100mm and height 2 times greater than diameter instandard set up. There is 150mm diameter Triaxialcell available as well for large sample sizes.
The cell has enough room to install internaltransducers or modification of the device foranisotropic and unsaturated tests. capacity of 2000 kPa is provided in order to coverall ranges of required cell pressure for ResonantColumn tests (Transparent version).
It includes of pressure resistance Through portsfor internal transducers for direct measurementat the sample like internal displacement, noncontact sensors, force sensors and etc. The cellcomes with Adapter-Set for requested samplediameters consisting of top plate, stainless steelbottom plate, hose connections, porous discs,and O-rings.
Inner Cell
The resonant column cell comes with an inner cellto surround sample with water or silicon oil, toavoid air (confining pressure gas ) penetrating therubber membrane into the sample.
The double cell does allow us to have water in theinner cell up to the top cap with a layer of siliconoil on top of the water. The outer cell confiningpressure is air. The water in the inner cell isto prevent air diffusion through the specimenmembrane and the silicon oil is to prevent airentering the water. This Inner cell is made of special transparentplexi-glass and can easily installed or removed in working time.
Sample Preparation Set
For each sample size, a sample preparation kitwould be delivered to enable the users to preparesample for the test.
Sample preparation kit for is Including of: • split former for non-cohesive materials • O-ring stretcher • Numbers of O-ring • suction sleeve device for cohesive materials • 100 pices of filter paper • numbers of membrane
Automatic Pressure Controlling System (vpc)
Fully automatic computer controlledMicroprocessor closed loop controlled airpressure-actuator with minimum one outputpressure port up to three independent outputpressure ports is used to generate cell pressure,back pressure, anisotropic pneumatic actuator orair pressure(unsaturated tests).
output Pressure:2000 kPa
Resolution:0.1 kPa
Pressure outlets:1, 2 or 3 outlets
Direct, menu-driven control through PC and alsothrough the integrated control touch panel ondevice.Fully automatic pressure adjustment throughintegrated SIEMENS-controller.
Calibration Set
In order to perform calibration, it is necessary to havethree aluminum calibration rods whose mechanicalproperties are known with diameter of 20 mm, 33 mmand 50 mm.
A Resonant test is performed on a calibration bar(calibration bar is located in place of the Specimen) inorder to determine polar mass moment of inertia ofdriving system Jo and JL.
Lifting Frame For Easy Cell Top Removal
Allows user to safely and easily move the Triaxial cell wall by using a mechanical Lifting System which isconnected to Triaxial cell (pulley and cable).No need to use any crane for cell removal.
Automatic Volume Measuring Device
High accuracy automatic Electronic VolumeChange Measuring device with control paneland capacity of 1700 kPa, 100 ml, Resolution:0.001/100 ml, Linearity: < 0.1 %
Data Acquisition And Power Amplifier Unit
The data acquisition unit and Power amplifier both are located in a box as a single unit for collectingdifferent measuring values like force, displacement, pressure, frequency, temperature and etc.Transducers and sensors providing analogous signals can be connected easily to the unit.
The power amplifier with high precision torsional drive system used to vibrate the top of the confinedsolid or hollow cylindrical soil specimen at frequencies up to 3000 Hz.