Electro hydraulic servo rock mechanics testing machine

For nearly half a century, geological testing professionals have regarded MTS as the industry standard for high-precision and high reliability rock testing.
Today, we continue to apply our over 40 years of experience to design and manufacture innovative solutions for various applications and budgetsElectro hydraulic servo rock mechanics testing machine.

Accurate and reliable design

VerifiedElectro hydraulic servo rock mechanics testing machine

The MTS 815 and 816 rock mechanics testing systems are confident in providing fully integrated solutions for geological material experts, with configurations capable of testing all types of rocks in both basic and highly complex applications.

The purpose of designing these systems is to test everything from soft sandstone to high-strength brittle rocks, combining a multifunctional servo hydraulic loading framework with precise digital controls, flexible software, and accessories for uniaxial and triaxial testing.

I hope these complete solutions can help you effectively manage and control the forces, pressures, and temperatures required for the current strict geological material assessment.

MTS 815 system

The MTS 815 system is highly suitable for uniaxial and triaxial rock testing, and is crucial for fossil fuel exploration and production, mining, and rock mechanics research. It has high axial force capability, with a rated compression force of up to 4600 kN and a rated tension of up to 2300 kN.

Overall, its high rigidity load frame, fixed crosshead, and single ended actuator make the system particularly suitable for studying carefully controlled fault behavior.

MTS 816 system

The MTS 816 system is designed for rock mechanics research experiments involving smaller specimens.

The system can be configured for single axis, three-axis, or direct shear testing, and its compact frame is easy to install in the laboratory.

The 816 system provides lower power capabilities than the 815 system, but it offers a more economical way to add rock testing capabilities to your laboratory project.

Flexible modular design

The MTS 815 and 816 testing systems include many features that help testing professionals conduct more extensive testing using a single system. The partition allows you to choose from a range of sample sizes. The load frame is pre designed for installing three-axis units. According to your needs, other accessories can be easily installed in various configurations. In addition, MTS can also customize the system according to specific needs.

MTS 815 testing system with 656 three-axis load sensor

MTS 816 testing system with direct shear tester

MTS can help you fully describe the characteristics of rock samples under common high temperature and high pressure conditions in underground environments.

Decades of professional knowledge in rock testing

Compared to other manufacturers, MTS has installed more high-pressure servo hydraulic rock testing systems around the world. To design these systems, we collaborated with respected rock mechanics researchers and geomechanical modeling experts in the industry. We also utilized the extensive knowledge and practical experience gained from engineering and manufacturing high-quality testing solutions in many other material testing industries, from aerospace to biomechanics.

Servo hydraulic innovation

The servo hydraulic load frame technology is crucial for rock mechanics testing. MTS adopted this technology decades ago and continues to innovate in servo hydraulic systems. The 815 and 816 systems represent our collective knowledge and experience, which is why they are able to provide the accuracy and reliability required for testing professionals to perform a wide variety and increasing number of rock mechanics tests.

Specialized services and support

To ensure that you receive expert assistance, MT S can provide large-scale, experienced service, support, and consulting personnel from any testing solution provider. In addition to basic services and maintenance, we also provide application engineering for professionals who can understand the subtle differences in rock testing. Our team also provides complete lifecycle management to maximize your technology investment return and help you meet new testing needs as economically and efficiently as possible.

World Industrial Design

The servo hydraulic load frame that constitutes the core of the 815 and 816 systems is the result of a global industrial design project. No matter which system suits your needs, you can safely and efficiently perform rock mechanics testing in a tightly controlled environment that emphasizes accuracy and ease of operation.

MTS System Technology

Integrated technology to improve accuracy, reliability, and repeatability

The MTS rock mechanics testing system has accurate, repeatable, and durable performance. The MTS testing system is renowned for its high uptime and reliable results, and we have also designed, improved, and fine tuned the testing system to assist our clients in addressing many challenging market conditions. This depth and breadth of practical experience have created a comprehensive product line, allowing rock testing professionals to meet all testing objectives with a single reliable source.

High stiffness load frame

In the 815 system, the load frame assembly includes a fixed crosshead mounted on two rectangular columns bolted to the base plate, forming an extremely rigid but independent frame. The single ended, double acting actuator integrated into the base plate has a stroke of 100 millimeters (4 inches) and is used for testing that requires large displacement. The framework assembly includes two feedback sensors - a differential pressure (P) sensor and an internal linear variable differential transformer (LVDT), which is used to control and measure the displacement of the actuator.

The impact resistant LexanTM door and sliding rear panel can retain debris without affecting visibility.

In the 816 system, the load frame assembly includes a fixed crosshead installed on four columns bolted to the base plate, forming a rigid independent frame that can easily insert and remove specimens and fixtures of various sizes. This system uses the same single ended, double acting actuators as the 815 system.

The testing area is surrounded by Lexan panels on all sides, and the frame itself is placed on a hard tabletop for easy setting of work height.

Clean and Silent Hydraulic Distribution

The Silent FloTM hydraulic power unit (HPUS) is capable of providing superior performance with a compact size while operating at extremely low noise levels. They are small and quiet, and can be installed anywhere in the laboratory. In fact, the Silent Flo HPUS has a sound intensity of 30 dB (A), which is quieter than conventional HPUS and requires very little space. In addition, the 815 system also comes with a remotely installed hydraulic service valve group (HSMS), which can reduce interference with acoustic measurement results.

Software with functionality *

The MTS mechanics application software provides a complete set of testing templates that can perform standard test sequences and analyses specified by ASTM and ISRM. These templates can guide you in testing, data collection, and report generation. With this software, you can also easily create your own custom templates. Based on the MTS 793 series application software, the MTS geomechanics package uses a highly flexible drag and drop user interface, which can simplify the testing process of building standards and non-standard.

Run time rate control allows you to increase or decrease load or strain rate during testing, thereby more strictly controlling post fault testing and increasing production.

The runtime plot displays the selected feedback, allowing for continuous monitoring of test progress.

Numerical Control

Multi functional FlexTest ® Digital controllers can provide the flexibility you need to meet full spectrum testing requirements and quickly adapt to evolving standards. The FlexTest controller has scalability and ease of use, providing high-speed closed-loop control, data acquisition, function generation, and sensor adjustment functions. It can perform reliable single channel and multi-channel rock mechanics testing across multiple sites.

Single axis attachment

The uniaxial testing package can be used for compression, strain measurement, circumferential strain measurement, indirect tensile testing (Brazilian test), direct tensile testing, and fracture toughness.

These test packages include test fixtures and related hardware, as well as sensors and application software.

Three axis attachments

The MTS triaxial rock testing component helps achieve high fidelity simulation of on-site conditions, such as high confining pressure, high temperature, high pressure pore fluids, and various specimen stress states, including elongation.

The attachment can be used to support triaxial testing, including compression, creep, tension, and deformation stress paths.

Rock extensometer

The MTS extensometer model 632.9X series is designed specifically for measuring rock strain under high pressure and high temperature, providing precise accuracy, control, and durability for revealing the deformation characteristics of geological materials.

Direct cutting instrument

Expanded the capability of the 816 type system with integrated MTS direct shear package, allowing cylindrical, prismatic, or irregularly shaped intact or jointed rock specimens to simultaneously experience normal and shear stresses.

This test kit includes a rigid, compact load reaction force frame, shear actuator, weight sensor optimized for direct shear, and shear box.

延伸能力

The MTS 815 and 816 rock mechanics testing systems are designed for special high demand applications.

They have multiple models and strength functions, providing high precision and reliability in various specific testing requirements.

815 type system

Hanging ear

The integrated structure is very suitable for testing fragile materials

Rigid fixed crosshead

Rectangular Column

Accuracy, parallelism alignment between crosshead and actuator surface to ensure correct loading.

Front safety door for easy access to the testing space

Auxiliary device label

Fatigue rated, single ended, double acting actuator with specialized sealing and bearing design, durable and long-lasting. Combined with directly bonded polymer bearings, it can reduce friction and maximize heat dissipation.

The differential pressure (? P) sensor provides force readings, but does not affect the stiffness of the load frame, and J is within ± 1% of the calibration range under loads above 1000 kN.

Calibrate the internal LVDT to achieve full size actuator travel for positioning control

Remote installation of hydraulic service valve group to reduce interference with acoustic measurement equipment

Large testing areas for uniaxial and triaxial testing

Anti impact Lexan panel

Rigid base plate

Emergency stop button

Vibration isolation pad

Specification

815 type testing system

Load frame model

315.01

315.02

315.04

compression ratio

Qianniu

1600

2700

4600

A thousand pounds

350

600

1000

Tension level*

Qianniu

1050

1350

2300

A thousand pounds

240

300

500

Displacement of actuator

millimeter

100

100

100

inch

4

4

4

Spring rate of load frame

Cow/meter

7.0 x 109

9.0 x 109

10.5 x 109

Pound per inch

4.0 x 107

5.0 x 107

6.0 x 107

Estimated Weight

kilogram

2614

4218

7590

pound

5762

9300

16,700

Floor loading volume (width x depth)

millimeter

737 x 432

889 x 521

991 x 610

inch

29 x 17

35 x 20.5

39 x 24

*Although the load frame components can generate the tension shown, the actual tension limit depends on the connection hardware (such as threaded joints) that connects the clamping device to the crosshead and actuator.

Specification

816 type testing system

Load frame model

316.01

316.02

316.04

compression ratio

Qianniu

500

1045

2046

A thousand pounds

110

235

460

Tension level*

Qianniu

291

667

1374

A thousand pounds

65

150

309

Displacement of actuator

millimeter

100

100

100

inch

4

4

4

Spring rate of load frame

Cow/meter

1.1 x 109

2.6 x 109

3.0 x 109

Pound per inch

6.2 x 106

1.5 x 107

1.7 x 107

Estimated Weight

kilogram

2380

3252

3822

pound

5250

7170

8426

Floor loading volume (width x depth)

millimeter

1168 x 813

1168 x 813

1295 x 1168

inch

46 x 32

46 x 32

51 x 46

*Although the load frame components can generate the tension shown, the actual tension limit depends on the connection hardware (such as threaded joints) that connects the clamping device to the crosshead and actuator.

816 type system

Cross head mounted actuator

Tightly coupled energy storage device

Servo valve

Four column fixed crosshead design

Single ended, double acting actuators

Low profile high stiffness force sensor, with accuracy within ± 0.5% of the calibration range

Differential pressure sensor (standard on 316.04 load frame), with J accuracy within ± 1% of the calibration range under loads above 1000 kN

Calibrate the internal LVDT to achieve full size actuator travel for positioning control

All sides are equipped with Lexan panels for easy access to the testing space

Emergency stop button

Rigid base plate

Rigid support platform

Vibration isolation pad

multi-functional application

uniaxial test

Uniaxial compression and compression after failure

The compression and deformation tests of cylindrical rock specimens require pressure plate fixtures, force sensors for low force tests (less than 1000 kN/200 klb) or pressure differential sensors for high force tests (greater than 1000 kN/200 klb), signal conditioners and cables, gaskets, and axial and circumferential strain measurement toolkits.

When designing a load transmission chain for high-pressure compression, rigidity should be maintained as much as possible to minimize the deformation energy stored in the frame and loading system components during testing of fragile materials.

This is particularly important for the behavior after testing failure, as the integrity of the test depends on preventing the failure specimen from losing control.

The force sensor is fatigue rated and used to accurately measure the applied load (± 0.1%). It has an integrated sensing structure that improves repeatability and linearity through heat treatment, and reduces hysteresis. Its multi column design improves sensitivity while maintaining high axial stiffness, overload capacity, and long-term stability. It can resist external forces and moments, improve accuracy, and allow for high lateral and overturning moment stiffness.

The characteristic of sensors is the large number of low stress ends to ensure low hysteresis and small end adhesion effects.

Testing/Standards

Uniaxial compressive strength test (ASTM D2938-86 and ISRM recommended method for determining rock uniaxial compressive strength)

Deformation of Rock Materials in Uniaxial Compression (ASTM D3148-86 and ISRM Recommended Method for Determining Deformation of Rock Materials in Uniaxial Compression)

Creep of cylindrical hard and soft rock specimens under uniaxial compression (ASTM 4341-84 and ASTM 4405-84)

Indirect tension (Brazilian test)

The indirect tension test configuration uses an indirect tension fixture, a force sensor with a load frame accessory kit, a signal conditioner, cables from the force sensor to the load frame, and six to eight washers, depending on the sample size and load frame model.

The indirect tension clamp has a lightweight but sturdy aluminum body (>RC 58), and its hardened end cap is ground flat (less than 0.0005 mm/mm on the contact line), thereby reducing stress concentration.

These specially designed end caps with specific dimensions have arc radii that match the contact area of the specimen to further reduce stress concentration and off-axis loads.

In addition, the self-aligning design of the fixture does not rely on the alignment of the load transmission system. On the contrary, it ensures correct alignment throughout the entire travel range of the fixture, guiding the large diameter chrome plated column through low friction bearings.

The spherical fixed washer at the top of the fixture can be used to prevent bending due to torque.

The force sensor is the same as the fatigue rated model used for compression testing.

Testing/Standards

ASTM standard D3967-86

ISRM recommends a method for determining indirect tensile strength through Brazilian testing

Direct tension

In direct tension testing, direct tension fixtures, force sensors, and washers are used. This fixture features sturdy, orthogonally mounted blade chains and spherical upper and lower joints to ensure load calibration along the central axis of the specimen.

The U-shaped clamp pin connection on the end cap allows for quick and convenient replacement of the specimen without the need to disassemble the fixture.

The end cap design ensures a uniform distribution of epoxy resin on the surface of the specimen end and around the specimen end (when greater adhesive strength is required).

When connecting the end cap to the specimen, calibration hardware should be provided to ensure calibration between the end caps.

Provide four sets of sample end caps. The force sensor is the same as the fatigue rated force sensor used for compression and indirect tensile tests.

Testing/Standards

» ASTM D-2936-84

ISRM recommends a method for determining the tensile strength of rock materials

fracture toughness

The fracture toughness test helps determine the critical stress intensity factor (KIc) of V-notch core samples in three-point bending configurations. This configuration uses a bending fixture, force sensor, three to seven washers (depending on the sample size, force sensor, and load frame), strain measurement kit, clamp type strain gauge, four blade kits for installing clamp type strain gauges on the sample, dual LVDT for load point displacement measurement average output, LVDT installation fixture and alignment tool, four signal conditioners, and cables.

Bending fixtures help locate strain and displacement sensors on the specimen to obtain accurate and reproducible results. Including a strain measurement kit for accurately measuring sample strain. Aligning the hardware helps to locate the displacement sensor and dual LVDT on the specimen, and correctly position the specimen on the fixture.

The fatigue rated force sensor has the same model as the sensor used in compression, indirect, and direct tensile tests.

Testing/Standards

Fracture toughness test (ISRM recommended method for determining the fracture toughness of V-shaped bending specimens, primary and secondary rocks)

Triaxial test

Triaxial compression/triaxial creep

The triaxial compression/creep test combines the above-mentioned uniaxial compression attachments with triaxial element components to simulate on-site stress, temperature, and pore fluid pressure, and further study the effects of these condition changes on the specimen.

The characteristic of MTS three-axis unit assembly is that it has a fatigue rated unit with a hydraulic control lift and lock cylinder that can be quickly opened and closed.

The bolted flange connection on the bottom plate ensures easy and secure closure of the container. The track and frame assembly are integrated with the load-bearing frame for easy installation and disassembly of the unit.

The design of the load transmission chain itself is to adapt to the extension test.

Electrical and fluid penetrations are suitable for high pressure and high temperature, and sample end caps can be used for high-pressure compression testing, tensile testing, pore fluid and permeability testing.

Testing/Standards

ASTM D2664-86 (Triaxial compressive strength of undrained core samples measured without void pressure)

ASTM D4406-84 (Creep Test of Rock Core Samples Under Triaxial Compression at Environmental or High Temperature)

ISRM recommends a method for determining the strength of rock materials in triaxial compression

Three-axis deformation stress path

The MTS rock mechanics testing system, triaxial attachments, and deflection test digital controls can be used to draw deformation stress paths.

Use standard equipment and direct sensor inputs to the deflection test controller to perform static hydraulic compression and triaxial compression.

The remaining stress paths use sensor inputs and the calculated input characteristics of the FlexTest controller.

The hydrostatic compression path can directly measure the bulk modulus.

If the volume and pressure of the pore fluid are measured, as well as the static water compaction point during pore collapse, Skempton's coefficient B and Biot's coefficient α can be obtained.

The triaxial compression path directly measures the Young's modulus and Poisson's ratio from the stress/strain curve, as well as data used to determine the shear failure surface and ductile yield surface.

The uniaxial strain compression path involves an experiment that represents the deformation that occurs when the rock is buried in a sedimentary basin or as a response to fluid extraction during oil and gas reserve extraction. This path provides data representing the approximate deformation of reservoir rocks during production, similar to the deformation of sediments or rocks in sedimentary basins, and provides data on pore collapse areas.

The constant K ratio compression represents the deformation path after producing reservoir rocks.

It provides data on pore collapse zones and can generate a constant pressure differential path or a constant average pressure path.

The constant differential stress path provides data to compare the effect of axial stress σ 1 on material properties with similar data obtained from the hydrostatic path (under equal stress conditions).