10.11 Stress_Model: Phillips Constitutive Model
PHILLIPS
Material_name = PHILLIPS Number_of_uniaxial_curves = ncurve, etc...
Finite deformation effects are not accounted for by this model.
Note Variable Name Type Default Description
Number_of_uniaxial_curves integer [1] Number of uniaxial curves 
1
Max_number_of_data_points integer [0] Maximum number of data points 3
Number_of_creep_curves integer [0] Number of creep curves 0
Max_number_of_creep_data integer [0] Maximum number of creep data 1
10.11.2 Material
Properties Data
Note Variable Name Type Default Description
Material_set_number integer [1] Material set number 
Numat
Mass_density real [0.0] Mass density 
Shear_modulus real [0.0] Shear modulus G
Bulk_modulus real [0.0] Bulk modulus B
Friction_angle real [0.0] Friction angle 
> 0.0
Cohesion real [0.0] Cohesive
coefficient c 0.0
Dilation_angle real [0.0] Dilation angle 
0.0
(1) Initial_stress
initial_stress_11 real [0.0] Component
11 (
)
initial_stress_22 real [0.0] Component
22 (
)
initial_stress_33 real [0.0] Component
33 (
)
initial_stress_12 real [0.0] Component
12 (
)
initial_stress_23 real [0.0] Component
23 (
)
initial_stress_31 real [0.0] Component
31 (
)
(cont’d)
(cont'd)
Note Variable Name Type Default Description
Solid_mass_density real [0.0] Mass density (solid phase) s
Fluid_mass_density real [0.0] Mass density (fluid phase) w
Fluid_bulk_modulus real [0.0] Fluid bulk modulus 
w
Porosity real [0.0] Porosity nw
K0_at_rest real [n /(1-n)] Lateral stress coefficient at rest.
K0_loading real [n /(1-n)] Lateral stress coefficient upon loading.
K0_unloading real [n /(1-n)] Lateral stress coefficient upon unloading.
Direction_of_anisotropy integer [3] Direction of principal anisotropy.
1 and NSD
Porosity_update list [off] Porosity update option
on / off
Failure_check list [on] Failure option
on / off
Critical_friction_angle real [0.0] Critical friction angle > 0.0
Primary_curve integer [1] Primary uniaxial stress-strain curve N1
1 and Nuniaxial_curve
Secondary_curve integer [N1] Secondary uniaxial stress-strain curve N2
1 and Nuniaxial_curve
Interpolation_option list [off] Interpolation option
on / off
Ref_fluid_pressure real [0.0] Pore fluid pressure multiplier pw
Pressure_load_time integer [1] Pore fluid pressure load time function
number
(cont'd)
(cont'd)
Note Variable Name Type Default Description
Saturation_multiplier real [0.0] Pore fluid saturation multiplier
Saturation_load_time integer [1] Pore fluid saturation load time function number
Critical_saturation real [0.0] Pore fluid critical saturation Sc
Ultimate_saturation real [0.0] Pore fluid ultimate saturation Su
Ultimate_curve integer [N2] Ultimate uniaxial stress-strain curve Sc < S < Su
1 and Nuniaxial_curve
Power_exponent real [0.0] Power exponent (Creep)
Creep_update list [off] Creep update
on / off
Creep_load_time integer [1] Creep load time function number
Creep_curve integer [1] Creep curve 1 and Ncreep_curve
(2) File_name string [none] File name (optional). Name must be
enclosed in quotation marks.
Notes/
(1) Tensile stresses are positive.
(2) This option allows the uniaxial stress-strain data and creep data to be read in from another file.
10.11.3 Uniaxial
Stress-Strain Curves and Creep Data
The uniaxial stress-strain data are
first input followed by the creep data.
Following are the required data records for input of the uniaxial
stress-strain curves:
Record 1: Identifying name for the following uniaxial
stress-strain data.
Record 2
Note Variable Default Description
N [0] Material
curve set number 1 and Nuniaxial_curve
NMAX(N) [0] Number of data points 3 and Nuniaxial_max
SCX(N) [0.0] Scaling factor for strains 0.0
SCY(N) [0.0] Scaling factor for stresses 0.0
Record(s) 3
(NMAX(N) sets)
Note Variable Default Description
STRAIN [0.0] Strain
STRESS [0.0] Stress
The creep data follow the uniaxial
data. Following are the required data
records for input of the creep curves:
Record 1: Identifying name for the following creep
data.
Record 2
Note Variable Default Description
N [0] Material curve set number 1 and Ncreep_curve
NMAX(N) [0] Number of data points 3 and Ncreep_max
SCX(N) [0.0] Scaling factor for stress 0.0
SCY(N) [0.0] Scaling factor for R0 0.0
Record(s) 3
(NMAX(N) sets)
Note Variable Default Description
STRESS [0.0] Stress
R0 [0.0] Reference time resistance R0
r [0.0] Time resistance number r
epsilon0 [0.0] 24 hrs strain at each load step epsilon0 (in %)
Notes . .