This example illustrates a rigid body falling under gravity onto a deformable body using pseudo-viscosity
###################################################
# This example illustrates a rigid blue body falling
# under gravity onto a deformable red body. This
# example highlights the use of psuedo-viscosity
# which adds numerical stability to normally unstable
# quasi-static contact problems.
###################################################
# Define parameters,regions,and coordinate system
fem def para;r;contact;example
fem def coord 3,1
fem def region;r;contact;example
fem def bases;r;contact;example
$REG=1;
################ MESHES ################
@object_list = ('blue','red');
foreach $component(@object_list)
{
# Read in meshes
fem def nodes;r;$component;example reg $REG
fem def elements;r;$component;example reg $REG
if($REG==2){fem up node deriv 1 linear reg $REG}
if($REG==2){fem up node deriv 2 linear reg $REG}
if($REG==2){fem up node deriv 3 linear reg $REG}
#if($REG==2){fem update scale_factors normalise reg $REG}
if($REG==2){fem change nodes scale by 2,2,2 reg $REG}
# Define fibre field (nj 4,5,6)
fem def fibre;r;$component;example reg $REG
fem def elements;r;$component;example fibre reg $REG
if($REG==2){fem change nodes rotate by -180 axis 0,0,1 reg $REG}
if($REG==2){fem change nodes translate by 400,494,0 reg $REG}
if($REG==2){fem change nodes translate by 200,260,1001 reg $REG}
fem ref xi 1 at 0.5 reg $REG
fem ref xi 2 at 0.5 reg $REG
fem ref xi 3 at 0.5 reg $REG
if($REG==1){fem change nodes translate by 0,30,0 reg $REG}
## Export meshes
#fem exp nodes;$component as $component reg $REG
#fem exp elements;$component as $component reg $REG
# Node groups
if($REG==1){fem group nodes 201..227 as FIXBLUE reg $REG}
if($REG==2){fem group nodes 103..104,107..108,229,231,244..246 as FIXTALL reg $REG}
if($REG==2){fem group nodes 101..102,105..106,228,230,232..243 as FIXT reg $REG}
# Method
fem def equa;r;$component;example reg $REG
fem def mate;r;$component;example reg $REG
fem def init;r;$component;example reg $REG
$REG=$REG+1;
}
# define contact parameters
fem def contact;r;contact;example
# Define solve for coupled
fem def solve;r;coupled;example coupled reg 1,2
$k=1;
# load steps
for ($i=1;$i<11;$i++)
{
if ($i>1)
{
fem def mate;r;blue$i;example
}
$CONVERGED=0;
while ($CONVERGED==0)
#for($j=1;$j<2;$j++)
{
######################################Projection
# Set contact Xi points on specified faces as 6x6 points
fem def xi;c contact_points faces 23,27,3,8 points 6 reg 1
# Define data at xi positions
fem def data;c from_xi
# Update slave info
fem update data field to slave
# Project onto target face
fem def xi;c closest_face faces 39,44,59,63 region 2
# store projection gap in data fields
fem update data field from gap region 2
# Update master info
fem update data field to master
# Place initial geometry YP(ny,3) into XP
FEM up geom from sol YP_index 3 to 1..3 reg 1,2
#####################################Mechanics problem
# Solve finite elasticity/contact problem
fem solve error 1.0D-01 iterate 20 coupled reg 1,2
# update XP from YP
FEM up geom from sol to 1..3 reg 1,2
#fem exp nodes;blue$k as blue reg 1
#fem exp nodes;red$k as red reg 2
$k++;
}
## Export final mesh
#fem exp nodes;blue_def$i as blue
#fem exp nodes;red_def$i as red reg 2
}
