INITIAL_DAMAGE_MAP

Initial conditions

Beta command

This command is in the beta stage and the format may change over time.

*INITIAL_DAMAGE_MAP
"Optional title"
coid
entype, enid, mapid, csysid, $t_{map}$, i${}_x$, i${}_y$, i${}_z$, $sf$
$x_0$, $y_0$, $z_0$, $x_1$, $y_1$, $z_1$, no_erode

Parameter definition

Variable
Description
coid
Command ID
entype
Entity type
options: P, PS
enid
ID of entity to which data will be mapped
mapid
ID of map containing damage values
csysid
Optional local coordinate system ID
default: global coordinates are used
$t_{map}$
Activation time
default: $t=0$
i${}_x$, i${}_y$, i${}_z$
Optional impulse vector that will be distributed inside the damaged region
default: not used
$sf$
Optional damage scale factor
default: 1
$x_0$
Mapping domain minimum x-coordinate
$y_0$
Mapping domain minimum y-coordinate
$z_0$
Mapping domain minimum z-coordinate
$x_1$
Mapping domain maximum x-coordinate
$y_1$
Mapping domain maximum y-coordinate
$z_1$
Mapping domain maximum z-coordinate
no_erode
Flag to deactivate erosion of empty space
options:
0 $\rightarrow$ erode elements in empty space
1 $\rightarrow$ do not erode elements in empty space

Description

This command is used in combination with OUTPUT_DAMAGE_MAP. The command takes the damage field that has been stored in the ASCII file damage_map1.k from the previous simulation and projects it on the new model. The file needs to be included to the model and correct map ID must be assigned.

Typical use is in multi-step blast and fragment loading simulations. The fragment loading requires a fine mesh and is of short duration. On the contrary a blast loading simulation requires longer simulation time but the mesh can be relatively coarse. Thus, a combined fragment and blast loading simulation would be computationally expensive (many elements and small time steps are required). However, if separated, a significant speed up can be achived by mapping the result from a local fragment impact simulation to a global blast loading model.

Damage values $-1$ represent empty space. Elements in empty space can either be eroded no_erode=0 or kept untouched no_erode=1.

Example

Blast loaded concrete slab with initial damage from fragment impacts

A global model of a blast loaded concrete slab. The local fragment impact simulation (step 1) can be found under examples in OUTPUT_DAMAGE_MAP. The damage is mapped to the global model and repeated at 20 random locations.

*UNIT_SYSTEM SI *PARAMETER %N_impact = 20, "number of fragment impacts" %m_tnt = 5, "charge mass" %soff = 1.0, "stand-off distance" # # --- TIME and OUTPUT --- # *TIME 0.01 # # --- MESH --- # *COMPONENT_BOX "slab" 1, 1, 150, 150, 15 -1.0, -1.0, -0.2, 1.0, 1.0, 0.0 *COMPONENT_PIPE "support" 2, 2, 1, 40, 5 0, 0, -0.25, 0, 0, -0.2, 1.0, 1.2 # # --- MATERIAL --- # *MAT_HJC_CONCRETE "concrete" 1, 2310.0, 14.86e9 0.79, 1.60, 0.61, 0.007, 50.5e6, 4.0e6, 1.0, 0.01 7.0, 16.0e6, 0.001, 800.0e6, 0.10, 0.04, 1.0, 85.0e9 -171.0e9, 208.0e9, 0 *MAT_RIGID 2, 7800.0 # # --- PART --- # *PART "slab" 1, 1, 0, 0, 0, 0, 2.0, 2.0 "support" 2, 2 # # --- BC --- # *BC_MOTION "support" 2 P, 2, XYZ, XYZ # # --- CONTACT --- # *CONTACT "all to all" 1 ALL, 0, ALL, 0 # # --- BLAST LOAD --- # *LOAD_AIR_BLAST 1 P, 1, [%m_tnt], 0, 0, [%soff] 1 # # --- DAMAGE MAP --- # *INCLUDE ../step_1/damage_map1.k ~repeat %N_impact *PARAMETER %x0 = -0.8 + 1.6*rnd %y0 = -0.8 + 1.6*rnd *COORDINATE_SYSTEM_FIXED [r1], [%x0], [%y0], 0.0 1, 0, 0, 0, 1, 0 *INITIAL_DAMAGE_MAP "impact [r1]" 1 P, 1, 1, [r1] -0.1, -0.1, -0.2, 0.1, 0.1, 0.0 ~end_repeat *END
Fragment loaded concrete slab with time offset and impulses

In this example, $t_{map}$ is being used to set a time offset at which the damage will be inflicted to the model. Also impulses are applied with parameter i${}_x$, i${}_y$ and i${}_z$.

*UNIT_SYSTEM SI *PARAMETER %N_impact = 20, "number of fragment impacts" %m_tnt = 5, "charge mass" %soff = 1.0, "stand-off distance" # # --- TIME and OUTPUT --- # *TIME 0.001 # # --- MESH --- # *COMPONENT_BOX "slab" 1, 1, 150, 150, 15 -1.0, -1.0, -0.2, 1.0, 1.0, 0.0 *COMPONENT_PIPE "support" 2, 2, 1, 40, 5 0, 0, -0.25, 0, 0, -0.2, 1.0, 1.2 # # --- MATERIAL --- # *MAT_HJC_CONCRETE "concrete" 1, 2310.0, 14.86e9 0.79, 1.60, 0.61, 0.007, 50.5e6, 4.0e6, 1.0, 0.01 7.0, 16.0e6, 0.001, 800.0e6, 0.10, 0.04, 1.0, 85.0e9 -171.0e9, 208.0e9, 0 *MAT_RIGID 2, 7800.0 # # --- PART --- # *PART "slab" 1, 1, 0, 0, 0, 0, 2.0, 2.0 "support" 2, 2 # # --- BC --- # *BC_MOTION "support" 2 P, 2, XYZ, XYZ # # --- CONTACT --- # *CONTACT "all to all" 1 ALL, 0, ALL, 0 # # --- DAMAGE MAP --- # *INCLUDE ../step_1/damage_map1.k ~repeat %N_impact *PARAMETER %x0 = -0.8 + 1.6*rnd %y0 = -0.8 + 1.6*rnd %toff = (r1-1) * 1.0e-5 *COORDINATE_SYSTEM_FIXED [r1], [%x0], [%y0], 0.0 1, 0, 0, 0, 1, 0 *INITIAL_DAMAGE_MAP "impact [r1]" 1 P, 1, 1, [r1], [%toff], 0, 0, -100 -0.1, -0.1, -0.2, 0.1, 0.1, 0.0 ~end_repeat *END