
Germany wille The direct shear test system is designed to determine the shear strength of intact or jointed rock or concrete specimens. Various samples in the form of cylindrical, prismatic, cubical or irregularly shaped segments of different sizes can be tested by this system. The closed loop servo control shear apparatus includes a special frame construction consisting of two stiff frames for vertical force and shear force, combined in a special configuration to avoid friction and torque.
The system includes a hydraulic power pack in combination with two separate valve systems, two-separate controllers and two low friction hydraulic cylinders. The shear boxes consist of a tilting free lower and upper shear frame, which is guided by linear bearings, a fixed upper shear frame and a guided load piston
The series of our direct shear systems consist of a load frame, direct shear test assemblies, servo hydraulic power pack, advanced digital controller and software for controlling the test. The specimen which is located in shear box would be subjected to the simultaneous normal and shear stresses which are controlled by software. The complete system is fully automated and controlled by our flexible and programmable GEOsys software. Various sensors, transducers, shear boxes and experiment options are available.
Direct Shear Frame
The frame is a high stiff frame which consists of 4 stiff columns and two actuators for vertical force and shear force, combined in a special configuration to avoid friction and torque to determine the shear strength and creep properties of rock samples, concrete, as well as any solid material.
The device is suitable for cylindrical, prismatic or irregular shaped pieces of solid or discontinuous rock cores. The system uses two independent servo-hydraulic actuators to apply axial and shear load to samples with highest accuracy possible. The servo- valves allow independent shear rates and enable the system to have a high-speed, closed-loop load control, displacement, position and volume or flow options. The system is capable of applying different stress paths or strain rates.
The actuators have integrated displacement stroke transducer for measurement of full stroke which controls the and speed.

The shear actuator is Closed-loop servo control of double acting (push/pull) with different capacities. Itis firmly connected to the shear box and located on Linear Guide bearing to have an easy movement of it for sample set up and also to reduce the friction in horizontal direction during the test.
Normal load stiff reaction frame mounted on sliding bearings to horizontal friction while keeping the normal load vertical throughout the full shear displacement.
Transducers
Different types and ranges of high-quality transducers are available to measure deformation and displacement for closed-loop system control e.g.:
Axial displacement transducer、Horizontal measurement transducer、High accuracy load cell for axial load、High accuracy load cell for shear load
Load Cells
We have variety range of low-profile laod cells which are able to suit your testing requirement sand are used for normal and shear forces in this machine. All load cells have factory Load calibration for full range, performed at the factory and the calibration Units are in kN. External Laod cells are delivered in variety.
Displacement Measurement
Shear and normal displacement of the shear box are recorded by multiple LVDTs which could be configured in different numbers per as the request of the user. The vertical displacement can be measured by 4 LVDTs which are located on sides (at 90 degrees) of the shear box and measure normal displacement, pitch and roll. The shear displacement LVDTs can be two numbers which are connected directly to lower shear box.
They can measure normal displacement, Dilatancy, shear displacement and rotations (when allowed)and normally have short stroke up to ± 25 mm and have factory calibration for full range which are performed at the factory and the calibration Units are in mm.
Shear Box
The shear boxes consist of a tilting free lower and upper shear frame, which is guided by linear bearings, a fixed upper shear frame and a guided load piston.
There are different available sizes: 300 x 300 mm or diameter 300 mm (shear boxes are exchangeable upon demand). The rectangular shear boxes are able to accept smaller specimens using special fixtures.
The upper shear frame is fixed, and bottom shear box is moveable and is mounted on Linear Guide bearing to minimize the friction in horizontal direction. The upper shear box which is connected to spherical seat platen has a lock mechanism to prevent any shear plane rotations. It can also be configured on request to have shear plane rotations in one or both of the roll and pitch axes if it is required.
Delivery Includes of:
• Clamping jaws for upper shearing box 300x300x150mm
• Clamping jaws for lower shearing box 300x300x150mm
• Pressure plate to apply the axial load
• Installation adapter for height compensation and reduction of the shear frame
• Note: Customized sample sizes are available on request.
Sample Handling Accessories
The system is delivered with special tools for the quick and easy handling of the shear box(installing and removing). Sample preparation and assembling of the shear box is explained in detail in our user manual. Sample preparation accessories and devices are available for various specimen sizes and on request, including: Core drilling machine Rock saw Grinding machine.

Hydraulic Power Pack
Our series of hydraulic power-packs supply smooth hydraulic fluid to actuators, hydraulic pressure intensifiers, and servo hydraulic testing machines to meet their testing system demands.
As the dynamic performance of a hydraulic system depends on input oil flow and pressure in cylinder therefor we offer a wide range of flowrates to meet required dynamic performance for your application. All components are mounted conveniently for easy access.
A key feature of our hydraulic power packs is that they offer demand-dependent flow-rate control, delivering at a constant pressure of 210, 280 or340 bar. They can locate beside or in greater distance from load frame.
An oil-to-water heat exchanger or air-cooling exchanger controls fluid temperature. A temperature switch turns the hydraulic power pack off when the temperature of the fluid exceeds a pre-set value – lights on a front panel are used to indicate temperature levels. Closed loop re-cooler system (chiller for Oil /Water Cooling) is available on request and can be integrated to the unit.

Front Panel Geography
indicators:Main switch、Emergency Stop、“Start”、“ON”(indicator light)、Reset、Manometer to operate pressures、Filter、Oil level (blinking)、Temperature (blinking)、Motor Temperature: The pump motor is overloaded、E-Stop: Illuminates after the emergency stop has been pressed

Air Cooling Method
Air cooling method uses a large fan which forces cooling air through the vanes of a radiator to reduce the temperature of hot oil quickly and efficiently. The hot oil is circulating in radiator to get cooler and gets working condition again. For large flow rate power pack, the fan generate larger amount of cooled air or it is recommended to use water cooling method.
Water Cooling Method
In this method a cooled water is reducing the temperature of oil to enable it to reach to working temperature condition. Depends on the flow rate of the power supply, the water flow rate be calculated correctly to give the good performance. The noise level of hydraulic supply units which use water cooling method is higher than Air cooled method. For example, the noise level of a hydraulic supply with flow rate of 7 LPM with water cooling method is 51dbwhich is super quiet while with air cooling is 62db (the values are measured in 1-meter distance form unit).
Digital Controller
Digital High-Speed High Resolution Expandable Real Time Control and data acquisition System 10KHz control and data acquisition and 24 bit resolution. The Dynamic controller is suitable for screw driven instruments(electromechanical) , hydraulic instruments with a valve driven with ±10 Volt and variety of sensors e.g. load cells, LVDTs, strain gauges, extensometers, thermocouples and etc.
The multi-functionality of the controller allows a modular design of the measurement and control parameters (sensors) via intelligent sensor plug, which store the calibration parameters, thus depending on the application can be used flexibly.

Main Features
• Up to 32 low-noise closed-loop control channels for static and dynamic tests
• up to 24-bit resolution channels for each test axis (e.g. force, displacement, pressure, strain)
• With digital controller parameterization and bumpless switching between all control functions
• Smooth changeover between all control functions
• Complete, simultaneous data transmission to avoid any data loss
• Digital adjustable controller parameters (P-I-D parameter)
• Simple and flexible test or setpoint parameter adjustment
• I/0 processing of externally connected
• Configuration and setup with PC software