WIPP-Type Models: Parallel-Plate Viscometer

Note

To view this project in 3DEC, use the menu command Help ► Examples…. Choose “CreepMaterialModels/ParallelPlateViscometerWIPP” and select “ViscometerWIPP.prj” to load. The project’s main data files are shown at the end of this example.

The parallel-plate viscometer test using the classical creep models is repeated to test the WIPP-type creep models (WIPP model, WIPP-Drucker model, and WIPP-Salt model). The analytical solution for the parallel-plate test assumes the viscosity is constant. In the WIPP-type creep models, the viscosity is dependent on the deviatoric stress, so a direct comparison cannot be made.

The WIPP model component is also tested in the WIPP-Drucker model (block zone cmodel wipp-drucker) and the WIPP-Salt model (block zone cmodel wipp-slat) for the viscometer test. The values of shear and tensile strength are set high to prevent plastic failure in the WIPP-Drucker model, and the values of initial and final density are set equal to prevent viscous compaction in the the WIPP-Salt model. The additional commands for these models are contained in data files. Upon execution of the data file with each model activated, results identical to those produced with the WIPP model are obtained.

The contours of \(x\)-velocity from 3DEC are shown in Figure 1.

Figure 1: Contours of x-velocity from the 3DEC WIPP model.

Data Files

viscometer.dat

model new
; file: viscometer.3dip-directionat
; Wipp viscosity - parallel plate test
;
model title
"Parallel-Plate Viscometer (WIPP model)"
model config creep
model large-strain off

block create brick 0 10 0 1 0 5
block zone generate edgelength 1.0

model save 'zoned'

block zone cmodel assign wipp
block zone property density 1 bulk 20.7e9 shear 12.4e9 temperature 300
block zone property constant-gas 1.987 activation-energy 12e3 exponent 4.9 constant-d 5.79e-36
block zone property constant-a 4.56 constant-b 127 creep-rate-critical 5.39e-8

;block zone property tension 1e10 friction-drucker 0.0 dilation-drucker 0.0 cohesion-drucker 1e10            ;  WIPP-Drucker properties
;block zone property compaction-0 0.0 compaction-1 0.0 compaction-2 0.0 bulk-final 20.7e9 shear-final 12.4e9 ;  WIPP-Salt properties
;block zone property density-salt 2600 density-final 2600                                                    ;  WIPP-Salt properties

block gridpoint apply vel-x = 0 range pos-x 0
block gridpoint apply vel-z 0 range pos-z 0
block gridpoint apply vel-x 0 range pos-z 5
block gridpoint apply vel-z -1e-4 range pos-z 5
block gridpoint apply force-x 2.25e5              range pos-x 10 pos-z 0
block gridpoint apply force-x 4.32e5 force-z -1.2e5 range pos-x 10 pos-z 0.9 1.1
block gridpoint apply force-x 3.78e5 force-z -2.4e5 range pos-x 10 pos-z 1.9 2.1
block gridpoint apply force-x 2.88e5 force-z -3.6e5 range pos-x 10 pos-z 2.9 3.1
block gridpoint apply force-x 1.62e5 force-z -4.8e5 range pos-x 10 pos-z 3.9 4.1
block gridpoint apply vel-y 0 range pos-y 0
block gridpoint apply vel-y 0 range pos-y 1

model creep active on
model creep timestep fix 1

model history creep time-total
model history mechanical unbalanced-maximum
block history velocity-x position 3 3 0
block history velocity-y position 3 3 0
block history stress-xx position 3.5 3.5 0.5
block history stress-yy position 3.5 3.5 0.5
block history stress-xy position 3.5 3.5 0.5
block history stress-zz position 3.5 3.5 0.5

model step 5000

model save "viscometer-wipp"