timprove shear script by isolating relevant parameters at top - Granular.jl - Julia package for granular dynamics simulation
(HTM) git clone git://src.adamsgaard.dk/Granular.jl
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---
(DIR) commit 9d7b77cc31093b7d6c8c87a496b6afa35cb35101
(DIR) parent 88d9a2d7f028f6db6738fee8147d234c3eb24c0f
(HTM) Author: Anders Damsgaard <andersd@riseup.net>
Date: Thu, 16 Nov 2017 08:56:52 -0800
improve shear script by isolating relevant parameters at top
Diffstat:
M examples/shear.jl | 60 +++++++++++++++++++++++--------
1 file changed, 45 insertions(+), 15 deletions(-)
---
(DIR) diff --git a/examples/shear.jl b/examples/shear.jl
t@@ -4,21 +4,58 @@ import Granular
import JLD
import PyPlot
+################################################################################
+#### SIMULATION PARAMETERS #
+################################################################################
+
# Common simulation identifier
const id_prefix = "test0"
+# Gravitational acceleration vector (cannot be zero; required for Step 1)
+const g = [0., -9.8]
+
+# Grain package geometry during initialization
+const nx = 10 # Grains along x (horizontal)
+const ny = 50 # Grains along y (vertical)
+
+# Grain-size parameters
+const r_min = 0.2 # Min. grain radius [m]
+const r_max = 1.0 # Max. grain radius [m]
+const gsd_type = "powerlaw" # "powerlaw" or "uniform" sizes between r_min and r_max
+const gsd_powerlaw_exponent = -1.8 # GSD power-law exponent
+const gsd_seed = 1 # Value to seed random-size generation
+
+# Grain mechanical properties
+const youngs_modulus = 2e7 # Elastic modulus [Pa]
+const poissons_ratio = 0.185 # Shear-stiffness ratio [-]
+const tensile_strength = 0.0 # Inter-grain bond strength [Pa]
+const contact_dynamic_friction = 0.4 # Coulomb-frictional coefficient [-]
+const rotating = true # Allow grain rotation
+
+# Normal stress for the consolidation and shear [Pa]
+const N = 10e3
+
+# Shear velocity to apply to the top grains [m/s]
+const vel_shear = 0.1
+
################################################################################
#### Step 1: Create a loose granular assemblage and let it settle at -y #
################################################################################
sim = Granular.createSimulation(id="$(id_prefix)-init")
-# Generate 10 grains along x and 50 grains along y, with radii between 0.2 and
-# 1.0 m.
-const nx = 10
-const ny = 50
-const r_min = 0.2
-const r_max = 1.0
-Granular.regularPacking!(sim, [nx, ny], r_min, r_max)
+Granular.regularPacking!(sim, [nx, ny], r_min, r_max,
+ size_distribution=gsd_type,
+ size_distribution_parameter=gsd_powerlaw_exponent,
+ seed=gsd_seed)
+
+# Set grain mechanical properties
+for grain in sim.grains
+ grain.youngs_modulus = youngs_modulus
+ grain.poissons_ratio = poissons_ratio
+ grain.tensile_strength = tensile_strength
+ grain.contact_dynamic_friction = contact_dynamic_friction
+ grain.rotating = rotating
+end
# Create a grid for contact searching spanning the extent of the grains
Granular.fitGridToGrains!(sim, sim.ocean)
t@@ -30,7 +67,6 @@ Granular.setGridBoundaryConditions!(sim.ocean, "impermeable", "north south",
Granular.setGridBoundaryConditions!(sim.ocean, "periodic", "east west")
# Add gravitational acceleration to all grains and disable ocean-grid drag
-const g = [0., -9.8]
for grain in sim.grains
Granular.addBodyForce!(grain, grain.mass*g)
Granular.disableOceanDrag!(grain)
t@@ -68,9 +104,6 @@ sim_init = deepcopy(sim)
#### Step 2: Consolidate the previous output under a constant normal stress #
################################################################################
-# Select a normal stress for the consolidation [Pa]
-N = 10e3
-
# Rename the simulation so we don't overwrite output from the previous step
sim.id = "$(id_prefix)-cons-N$(N)Pa"
t@@ -160,9 +193,6 @@ sim_cons = deepcopy(sim)
#### Step 3: Shear the consolidated assemblage with a constant velocity #
################################################################################
-# Select a shear velocity for the consolidation [m/s]
-const vel_shear = 0.1
-
# Rename the simulation so we don't overwrite output from the previous step
sim.id = "$(id_prefix)-shear-N$(N)Pa-vel_shear$(vel_shear)m-s"
t@@ -171,7 +201,7 @@ Granular.zeroKinematics!(sim)
# Prescribe the shear velocity to the uppermost grains
for grain in sim.grains
- if grain.lin_pos[2] <= fixed_thickness
+ if grain.lin_pos[2] >= sim.walls[1].pos - fixed_thickness
# do not allow changes in velocity
grain.fixed = true