Shear Stage Setup (continued)
You input the ‘t95’ value (determined from the Consolidation graph) to calculate the Shearing Speed. A manually entered Shear Speed can also be specified if required. The Reversing Speed to reverse the machine to the starting position after the Shear Stage Stop Conditions have been satisfied can be input manually or calculated automatically.
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. In the Ramp schedule, it is usual to ramp and then maintain the Vertical Force at the required value and maintain or ignore the Horizontal Load and Back Pressure (although they may be changed if required).
It is usual to use Active Height Control for the Dynamic Simple Shear test (where the Vertical Displacement is mainained whilst the Horizontal Load is cycled and the Back Pressure ignored. However, other combinations are allowed.
You can select from a number of different waveforms for the Cyclic schedule (Sinusoidal, Triangular, Square Wave, Haversine, Saw-Tooth or User-Defined), and then specify 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.
The Cyclic stage will terminate on completion of the cycle count or end prematurely when either the Shear strain exceeds a specified percentage, and/or the Vertical travel ever exceeds the amplitude by a specified percentage and/or the Horizontal travel ever exceeds the amplitude by a specified percentage. The next schedule can be started straightaway and a confirmatory e-mail sent if required.