Stress Path Stage Setup
The Stress Path Test does not normally form part of a standard Dynamic (Cyclic) Triaxial Test and is not therefore selectable by default, but may be included if required. The Stress Path Test consists of one or more schedules using either the Cambridge or MIT version of the test.
Each schedule consists of a Target Total Stress and Target Deviator Stress to be achieved within a specified time period by applying a calculated required Cell Pressure, Back Pressure and Load and a graph is available to show the expected stress path. The Stress Path stage completion may be specified. The Stress Path stopping conditions can depend on the Deviator Stress and/or Axial strain values and/or a specified maximum time.
Dynamic Testing Stage Setup
The Dynamic Testing Stage will consist of one or more Ramp and Cyclic schedules where you Ramp to the required starting conditions and then carry out the required cyclic test. It is usual to ramp and maintain the Cell and Back Pressure and the Vertical Force (or Vertical Displacement), although one or more may be maintained at their current value.
The Cyclic schedule will require the waveform to be specified (Sinusoidal, Triangular, Square Wave, Haversine, Saw-Tooth or User-Defined), together with the Cycle Count, Data Logging Rate, Frequency and Amplitude.
The User-defined waveform can specify up to 1000 points, each specifying a Time (in msecs) and an equivalent Setpoint (either Displacement (mm) or Force (kN) dependent upon the Control Option) with movement advised to be relative to the current feedback of the sensor’s position.
Because the implementation of a Dynamic Cyclic schedule is to a great extent up to the User’s own requirements, the User specifies the particular stop condition(s) for the schedule by a variable(s) being tested logically to a threshold level(s).