This example illustrates two host meshes being deformed to ensure no slave overlap
#####################################################
# This example illustrates two host bodies coming
# into contact. Finite deformation mechanics is
# solved for the two hosts with constraints activated
# to ensure that the two slave bodies embedded inside
# do not overlap. This example illustrates the idea
# behind the FFD-mechanics problem. Also highlighted
# is the use of augmentations to improve the contact
# problem.
#####################################################
fem def para;r;FARO;example
fem def region;r;FARO;example
fem def coord 3,1
fem def base;r;collapsed;example
$REG=1;
################ MESHES ################
# object_list
@object_list = ('host_one','host_two','one','two');
foreach $component(@object_list)
{
# Mesh
fem def node;r;$component;example region $REG
fem def element;r;$component;example region $REG
# Align meshes
if($REG==2){fem change nodes translate by -8.5,0,0 reg $REG}
if($REG==4){fem change nodes translate by -8.5,0,0 reg $REG}
# Update node derivatives
fem update node deriv 1 linear reg $REG
fem update node deriv 2 linear reg $REG
fem update node deriv 3 linear reg $REG
fem update scale_factors normalise reg $REG
# Create node groups
if($REG==1){fem group nodes 201,202,205,206 as PREONE reg $REG}
if($REG==1){fem group nodes 201..208 as ALLONE reg $REG}
if($REG==2){fem group nodes 103,104,107,108 as PRETWO reg $REG}
if($REG==2){fem group nodes 101..108 as ALLTWO reg $REG}
# Define fibres
fem def fibre;r;$component;example region $REG
fem def elem;r;$component;example fibre region $REG
# Define fields
fem def field;r;$component;example region $REG
fem def elem;r;$component;example field region $REG
## Export host mesh
#fem exp nodes;zero_$component as $component region $REG;
#fem exp elem;zero_$component as $component region $REG;
# Define equation, material and initial conditions
# Defining ipequa for slave bodies (reg 3&4) ensures
# they are defined as contact bodies for gap calculations
fem def equa;r;$component;example reg $REG
if($REG==1){fem def mate;r;$component;example reg $REG}
if($REG==2){fem def mate;r;$component;example reg $REG}
if($REG==1){fem def init;r;$component;example reg $REG}
if($REG==2){fem def init;r;$component;example reg $REG}
# Put initial host geometry into fields 1,2,3
fem update field 1 reg $REG subst geometry x reg $REG;
fem update field 2 reg $REG subst geometry y reg $REG;
fem update field 3 reg $REG subst geometry z reg $REG;
fem update field 4 reg $REG subst geometry x reg $REG;
fem update field 5 reg $REG subst geometry y reg $REG;
fem update field 6 reg $REG subst geometry z reg $REG;
fem update field 7 reg $REG subst geometry x reg $REG;
fem update field 8 reg $REG subst geometry y reg $REG;
fem update field 9 reg $REG subst geometry z reg $REG;
# Define slave xi points inside host
if($REG==3){fem def xi;c nodes contain of $REG in 1 loose}
#if($REG==3){fem def xi;w;$component nodes contain of $REG in 1}
if($REG==4){fem def xi;c nodes contain of $REG in 2 loose}
#if($REG==4){fem def xi;w;$component nodes contain of $REG in 2}
$REG=$REG+1;
}
#######################################
# define contact parameters
fem def contact;r;contact;example
# Define solve for two host bodies
fem def solve;r;contact;example coupled reg 1,2
# Load steps
for ($j=1;$j<11;$j++)
{
# Control step size
if ($j<5){$k=0.1}
else {$k=0.05}
# Prescribe translation step
fem change nodes translate by $k,0,0 node PREONE reg 1
fem change nodes translate by -$k,0,0 node PRETWO reg 2
# Update slave one in host and export
fem update field 1 reg 1 subst geometry x reg 1;
fem update field 2 reg 1 subst geometry y reg 1;
fem update field 3 reg 1 subst geometry z reg 1;
fem update geometry x reg 1 subst field 4 reg 1
fem update geometry y reg 1 subst field 5 reg 1
fem update geometry z reg 1 subst field 6 reg 1
fem def xi;r;one;example nodes contain of 3 in 1 reg 3
fem update mesh position fit of 3 in 1
fem update geometry x reg 1 subst field 1 reg 1
fem update geometry y reg 1 subst field 2 reg 1
fem update geometry z reg 1 subst field 3 reg 1
fem update field 4 reg 1 subst geometry x reg 1;
fem update field 5 reg 1 subst geometry y reg 1;
fem update field 6 reg 1 subst geometry z reg 1;
# Update slave two in host and export
fem update field 1 reg 2 subst geometry x reg 2;
fem update field 2 reg 2 subst geometry y reg 2;
fem update field 3 reg 2 subst geometry z reg 2;
fem update geometry x reg 2 subst field 4 reg 2
fem update geometry y reg 2 subst field 5 reg 2
fem update geometry z reg 2 subst field 6 reg 2
fem def xi;r;two;example nodes contain of 4 in 2 reg 4
fem update mesh position fit of 4 in 2
fem update geometry x reg 2 subst field 1 reg 2
fem update geometry y reg 2 subst field 2 reg 2
fem update geometry z reg 2 subst field 3 reg 2
fem update field 4 reg 2 subst geometry x reg 2;
fem update field 5 reg 2 subst geometry y reg 2;
fem update field 6 reg 2 subst geometry z reg 2;
fem update solution from geometry substitute reg 1,2
$CONVERGED=0;
while ($CONVERGED==0)
#for ($z=1;$z<1;$z++)
{
######################################################Contact setup
# Define contact points on slave one (face=16)
fem def xi;c contact faces 16 points 6 reg 3
# Define data at xi positions
fem def data;c from_xi reg 3
# Calculate xi in slave host
fem def xi;c closest reg 1
# Update slave info
fem update data field to slave reg 1
# Project onto target face (master surface)
fem def xi;c closest_face faces 21 reg 4
# Store projection gap in data fields
fem update data field from gap reg 4
# Change Master object to host
# Create data from xi points
fem def data;c from_xi reg 4
# Generate xi in host
fem def xi;c closest reg 2
# Update master info
fem update data field to master reg 2
######################################################Solve mechanics
# Place initial geometry YP(ny,3) into XP
FEM up geom from sol YP_index 3 to 1..3 reg 1,2
if ($j<7){
fem solve error 0.01 iterate 1 coupled reg 1,2
} else {
if ($j==7) {fem def contact;r;contact_2;example}
fem solve error 0.01 iterate 15 coupled reg 1,2
}
# Update XP from YP
FEM up geom from sol to 1..3 reg 1,2
# Update slave one in host and export
fem update field 1 reg 1 subst geometry x reg 1;
fem update field 2 reg 1 subst geometry y reg 1;
fem update field 3 reg 1 subst geometry z reg 1;
fem update geometry x reg 1 subst field 4 reg 1
fem update geometry y reg 1 subst field 5 reg 1
fem update geometry z reg 1 subst field 6 reg 1
fem def xi;r;one;example nodes contain of 3 in 1 reg 3
fem update mesh position fit of 3 in 1
fem update geometry x reg 1 subst field 1 reg 1
fem update geometry y reg 1 subst field 2 reg 1
fem update geometry z reg 1 subst field 3 reg 1
fem update field 4 reg 1 subst geometry x reg 1;
fem update field 5 reg 1 subst geometry y reg 1;
fem update field 6 reg 1 subst geometry z reg 1;
# Update slave two in host and export
fem update field 1 reg 2 subst geometry x reg 2;
fem update field 2 reg 2 subst geometry y reg 2;
fem update field 3 reg 2 subst geometry z reg 2;
fem update geometry x reg 2 subst field 4 reg 2
fem update geometry y reg 2 subst field 5 reg 2
fem update geometry z reg 2 subst field 6 reg 2
fem def xi;r;two;example nodes contain of 4 in 2 reg 4
fem update mesh position fit of 4 in 2
fem update geometry x reg 2 subst field 1 reg 2
fem update geometry y reg 2 subst field 2 reg 2
fem update geometry z reg 2 subst field 3 reg 2
fem update field 4 reg 2 subst geometry x reg 2;
fem update field 5 reg 2 subst geometry y reg 2;
fem update field 6 reg 2 subst geometry z reg 2;
}
## host
#fem exp nodes;host_one_$j as host_one reg 1
#fem exp nodes;host_two_$j as host_two reg 2
# Update slave one in host and export
fem update field 1 reg 1 subst geometry x reg 1;
fem update field 2 reg 1 subst geometry y reg 1;
fem update field 3 reg 1 subst geometry z reg 1;
fem update geometry x reg 1 subst field 4 reg 1
fem update geometry y reg 1 subst field 5 reg 1
fem update geometry z reg 1 subst field 6 reg 1
fem def xi;r;one;example nodes contain of 3 in 1 reg 3
fem update mesh position fit of 3 in 1
#fem exp nodes;one_$j as one region 3
fem update geometry x reg 1 subst field 1 reg 1
fem update geometry y reg 1 subst field 2 reg 1
fem update geometry z reg 1 subst field 3 reg 1
fem update field 4 reg 1 subst geometry x reg 1;
fem update field 5 reg 1 subst geometry y reg 1;
fem update field 6 reg 1 subst geometry z reg 1;
# Update slave two in host and export
fem update field 1 reg 2 subst geometry x reg 2;
fem update field 2 reg 2 subst geometry y reg 2;
fem update field 3 reg 2 subst geometry z reg 2;
fem update geometry x reg 2 subst field 4 reg 2
fem update geometry y reg 2 subst field 5 reg 2
fem update geometry z reg 2 subst field 6 reg 2
fem def xi;r;two;example nodes contain of 4 in 2 reg 4
fem update mesh position fit of 4 in 2
#fem exp nodes;two_$j as two reg 4
fem update geometry x reg 2 subst field 1 reg 2
fem update geometry y reg 2 subst field 2 reg 2
fem update geometry z reg 2 subst field 3 reg 2
fem update field 4 reg 2 subst geometry x reg 2;
fem update field 5 reg 2 subst geometry y reg 2;
fem update field 6 reg 2 subst geometry z reg 2;
}
