Dynamic Back Pressure Direct Simple Shear Apparatus
The Direct Simple Shear System functions within a pressure chamber, enabling the application of confining pressures to the specimen with controlling of the sample pore pressure. The confining pressure can be servo-controlled using volume changes or other sensors as feedback. Additionally, reinforced membranes can be utilized if desired.
It can contains the different sample sizes in Simple shear version or in direct shear ones.
To avoid measurement errors caused by friction from linear bearings during axial and shear load testing, the system has been optimized compared to standard internal load cells by incorporating a 3D internal load cell. This device, specially developed by Wille Geotechnik, accurately measures forces in both vertical and horizontal directions simultaneously, without any interference. The load is protected against air pressure but not against water pressure.
- Features
- Specifications
- Software
- Standards
- Applications
- High Stiffness robust true triaxial cell with cell pressure up to 2 MPa
- Large Front Window for observation of sample
- Two (2) cyclic Electromechanical actuators for applying normal and shear loads
- Electrical feed-throughs for all internal sensors
- Passive or active height control
- 2 number of rigid bars built into system to maintain rigidity of machine
- Minimal rotation of Top cap during shearing
- Closed loop controlled normal and shear stress
- Low friction sample slip rings for specimen confinement (k0 condition)
- Performs drained (constant load) and undrained (constant volume) tests
- Two porewater ports at top and bottom for saturated conditions
- Porous discs with different roughness and surface are available i.e. plane, grooves, ridges and embedded pins
- Unique shear loading measurement using two multi directional load cells
- High quality and low friction double linear guides used to ensure strength and alignment without tilting in normal and shear directions
- High speed dynamic controller (10 kHz) for monitoring of measured values and closed loop control e.g. load, displacement, position
- Applies different types of wave form like: Sinusoidal, Square, Triangular, Haversine, Saw Tooth, Inverted Saw Tooth, Rectangle, and User Defined wave forms.
- Real-time data and graph display
- Ethernet Port for fast data transferring to PC
- Safety functions to prevent overload and over travel
|
Load type |
Electromechanical |
|
Normal force |
5kN / 10kN |
|
Shear force |
5kN / 10kN |
|
Accuracy class |
0.1% |
|
Force resolution |
<0.00001kN |
|
Frequency |
0.0001 up to 5 Hz |
|
Max. Back pressure |
Up to 1000 kPa |
|
Resolution |
0.01 N |
|
Max. settlement |
25mm (+/- 12.5 mm) |
|
Max. Shear displacement |
30 mm (+/- 15 mm) |
|
Displacement resolution |
0.001mm |
|
Spindle Stroke |
50mm |
|
Circular Sample Sizes |
Ø 50 mm Ø 50,5mm(20.00 cm²) Ø 60 mm (28.27 cm²) Ø 63 mm (31.2 cm²) Ø 66.8 mm (35.0 cm²) Ø 70 mm Ø 71.4 mm (40 cm²) Ø 79 mm (50 cm²) Ø 94.9 mm (70 cm²) Ø 100mm |
|
Computer Interface |
Ethernet |
GEOsys is designed for closed-loop controlled static & Dynamic tests for all test applications in material testing, such as stress-controlled, strain-controlled, any kind of waveforms like sine, rectangle, triangle, and predefined waves.
It is controlling and data acquisition software and also has different modules to run tests according to ASTM.
Control Parameters: The normal load (axial) and Shear load (Horizontal) can be operated in constant, ramp or cycle modes in three different operating modes:
- Velocity control
- Force control
- Displacement control
Depends on the requirement of the customer one or several modules would be delivered with main software, such as:
- Data Acquisition, processing and device management (DPD) Module
- Consolidation Stage (Single stage, multiple stage or over consolidation mode)
- Static Shear module (Displacement or stress controlled)
- Cyclic simple shear test Constant Normal Stress test
- Constant Normal Height test (active height control)
- Constant normal stiffness test (CNS)
- Shear stress-controlled test (constant, ramp and cyclic)
- Shear displacement control (constant, ramp and cyclic)
- Calculation of shear stresses
- Low speed creep testing
- Unsaturated tests
- Not available
- Detailed information will follow soon