The Benefits of Automated Dynamic Testing (Cyclic)

Dynamic Testing (both Triaxial and Shear) is a relatively new area of soil testing which requires considerable computing power due to the amount of data produced. Some years ago, this required a large amount of equipment – but the improvements in computing power and VJ Tech technological and software advancement have made Dynamic testing (Cyclic) more efficient and affordable for the laboratory.

This enables simulation of many different subsurface environments where repetitive forces are in action, from traffic across bridges and other similar structures, earthquakes, offshore wind farms, oil rigs, coastal erosion and numerous other applications.

VJ Tech Innovations For Dynamic Testing

We currently supply two primary types of Advanced Soil Testing Equipment in the form of Dynamic (Cyclic) Equipment; Dynamic (Cyclic) Triaxial Testing and Dynamic (Cyclic) Simple Shear Testing.

Dynamic (Cyclic) Triaxial Testing

VJ Tech offer 3 variants of Dynamic (Cyclic) Triaxial Test System, all with a Dynamic Servo Controller for control of an actuator producing high speed cyclic motion, with the whole System controlled over a network by the Clisp Studio csDYNA software module. They are;

• The Dynamic (Cyclic) Triaxial Test System with a VJ Tech Load Frame (pictured)
• The Dynamic (Cyclic) Triaxial Test System with a Basic Frame
• The Dynamic (Cyclic) Triaxial Test System (Hydraulic) with a Hydraulic Power Pack

csDYNA Features:

• Conforms to ASTM D3999-11 & ASTM D5311-11
• Software supports the single axis electromechanical, dual axis electromechanical and single axis hydraulic machines
• Saturation, Consolidation and Dynamic stages
• Optional Stress Path stage
• Configurable test automation
• Saturation Step method
• Saturation Ramp Method (Ramped Cell/Back pressure with time)
• Isotropic Consolidation
• Optional Anisotropic Consolidation (with k0)
• On screen measurement of t100, cohesion & angle of friction values
• Customisable System Units
• Easy instrument and equipment setup and calibration
• Tests can be set up and run on an individual client, job, borehole and sample basis
• Easy test setup using wizard style Assistant
• User configurable data logging
• E-mail test status
• Export and Import of Tests
• Live view of sensor readings and status
• Live Data Views:
• • Saturation Raw Data View (Measured Input Parameters, Calculated B-Value)
  • Consolidation Data View (Measured Input Parameters, Calculated PWP Dissipation, PWP Change & Volume Change)
  • Isotropic Consolidation Results View (Consolidation, Compressibility, Shear Machine Speed and Specimen Corrections)
  • Stress Path Data View (Measured Input Parameters, Calculated Deviator Stress, Total Stress, Effective Stress Ratio & Axial Strain)
  • Dynamic Testing Data View (Measured Input Parameters, Calculated Deviator Stress, Effective Stress Ratio & Axial Strain)
  • Dynamic Modulus & Damping Results (Damping Coefficient, Young's Modulus, Cyclic Shear Strain, Poisson's Ratio, Shear Modulus (Low Strain))

• Live graphical display of logged and calculated data:
• • Saturation Raw Data Graph (Time vs PWP Input)
  • Saturation Results Graph (Cell Pressure Input vs B-Value)
  • Isotropic Consolidation Graph (Time vs Volume Change)
  • Stress Path Graph (Time vs Effective Axial Stress)
  • Stress Path Summary Graph (Total Stress vs Deviator Stress)
  • Dynamic Data Graph (Time vs Load Input)
  • Dynamic Loading Hysteresis Graph (Sample Height Change vs Current Load)
  • Dynamic Modulus & Damping Graph (Damping Ratio vs Shear Modulus)

• Live tabular display of logged and calculated data:
• • Saturation Data Table (Time, Pore Water Pressure Input, Cell Pressure Input, Volume Input, Cell Pressure Volume Input, Back Pressure Input)
  • Saturation Results Table (Cell Pressure Input, Back Pressure Input, Pore Water Pressure Input, Volume Change, B-Value)
  • Isotropic Consolidation Table (Time, Pore Water Pressure Input, Volume Input, PWP Dissipation, Volume Change)
  • Stress Path Data Table (Time, Pore Water Pressure Input, Load Input, Cell Pressure Input, Strain Input, Back Pressure Input, Axial Strain, Total Stress, Shear Stress, Deviator Stress, Normal Stress)
  • Stress Path Summary Table (Target Total Stress, Target Deviator Stress, Total Stress, Deviator Stress)
  • Dynamic Data Table (Time, Cycle Count Load, Cycle Count Back, Cycle Count Cell, Pore Water Pressure Input, Load Input, Cell Pressure Input, Strain Input, Back Pressure Input, Current Load, Sample Height Change, Axial Strain, Deviator Stress)
  • Dynamic Modulus and Damping Properties Table (Deformation, Damping Ratio, Shear Modulus)

• User configurable views, graphs and tables (customisable from Input, Measured and Result data)
• Optional customised presentation reports on request

Dynamic (Cyclic) Simple Shear Testing

The Dynamic (Cyclic) Simple Shear Test System uses a Dynamic Simple Shear apparatus and dual axis Dynamic Servo Controller for control of two actuators producing high speed cyclic motion, with the whole System controlled over a network by the Clisp Studio csDYNADSS software module (pictured).

VJ Tech also offer the Dynamic (Cyclic) Simple Shear Test System uses a Dynamic Simple Shear apparatus and dual axis Dynamic Servo Controller for control of two actuators producing high speed cyclic motion, with the whole System controlled over a network by the Clisp Studio csDYNADSS software module

csDYNADSS Features:

• Conforms to ASTM D6528-07
• Direct Simple Shear Tests (static/dynamic)
• Consolidation and Shear stages for up to 4 specimens
• Automatic start/stop of test/machine
• Customisable System Units
• Easy instrument and equipment setup and calibration
• Tests can be set up and run on an individual client, job, borehole and sample basis
• Easy test setup using wizard style Assistant
• User configurable data logging
• E-mail test status
• Export and Import of Tests
• Live view of sensor readings and status

• Live Data Views:
• • Consolidation Data View (Measured Input Parameters, Settlement, Voids Ratio, t95, Normal Stress)
  • Shear Data View (Measured Input Parameters, Vertical Settlement, Horizontal Displacement, Shear Stress, Normal Stress, Shear Strain)
  • Shear Results Data View (Peak Shear Stress, Settlement at Peak Shear Stress, Vertical Settlement, Voids Ratio)

• Live graphical display of logged and calculated data:
• • Consolidation Graph (Time vs Axial Strain)
  • Shear Graphs:
  • • Stress Strain Curve (Shear Strain vs Shear Stress)
    • Normal Stress Graph (Time vs Normal Stress)
    • Axial and Shear Stress Curve (Effective Axial Stress vs Shear Stress)
    • Logarithmic Shear Modulus & Strain Graph (Shear Strain vs. Secant Shear Modulus)

• Live tabular display of logged and calculated data:
• • Consolidation Table (Time, Vertical Displacement Input, Vertical Load Input, PWP Input, Settlement, Axial Strain, Normal Stress)
  • Shear Table (Time, Horizontal Displacement Input, Horizontal Load Input, Vertical Displacement Input, Vertical Load Input, PWP Input, Horizontal Displacement, Vertical Settlement, Shear Stress, Normal Stress, Shear Strain, Secant Shear Modulus, Axial Strain)

• User configurable views, graphs and tables (customisable from Input, Measured and Result data)
• Standard predefined presentation reports:
• • Summary Report
  • Consolidation Graph
  • Consolidation Table
  • Shear: Strain vs. Stress and PWP Graph
  • Shear: Log Strain vs. Log Shear Modulus Graph
  • Shear: Effective Axial Stress vs Shear Stress Graph
  • Shear: Shear Strain vs. G/Effective Control Stress Graph
  • Shear Table