Example 5j5: Using line search with contact mechanics

This example demonstrates how line search can be used when solving a contact mechanics problem. A subroutine has been created at the top of the COM file where the projection commands are saved. This routine is called multiple times (from CMISS) during line search iterations to calculate the updated contact pressure. The name of the COM file is specified in the IRSOLV file.

The comfile run by this example is as follows:

#################################################################
# Set echo on so that commands do not get output to the terminal,
# especially when the projection commands are called multiple
# times from CMISS when doing line search.
#################################################################
set echo on;

# If the example path is not set, default to current directory
if (!defined $example) {
    $example = "./";
}
# Drop off the trailing / in the example path
$chopped = chop $example;
if ($chopped ne "/") {
    $example .= $chopped;
}

### Subroutine for projection
sub project{

    # update XP from YP
    FEM up geom from sol to 1..3 reg 1,2

    fem def xi;c contact_point faces SLAVE_FACE points 4 reg 1

    # Define data at xi positions, calculates xi 
    fem def data;c from_xi

    # Update slave info, Z_CONT & Z_CONT_LIST
    fem update data field to slave

    # Project onto target face (Region 2)
    fem def xi;c closest_face faces MASTER_FACE external region 2
 
    # store projection gap in data fields, calculates gap
    fem update data field from gap region 2  
 
    # Update master info, Z_CONT & Z_CONT_LIST
    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

}

if ($LINESEARCH==1){

  #################################################################
  # Set echo on so that commands do not get output to the terminal,
  # especially when the projection commands are called multiple
  # times from CMISS when doing line search.
  #################################################################
  set echo on;
  &project;

} else {

  #################################################################
  # Set echo on so that commands do not get output to the terminal,
  # especially when the projection commands are called multiple
  # times from CMISS when doing line search.
  #################################################################
  set echo on;

  fem def para;r;contact;example
  fem def coor 3,1
  fem def regi;r;regi;example

  fem def base;r;tricubic;example

  fem define node;r;block1;example reg 1
  fem define elem;r;block1;example reg 1
  fem def fibre;r;block1;example reg 1
  fem def elem;r;block1;example fibre reg 1

  #fem expor node;slave as slave reg 1
  #fem expor elem;slave as slave reg 1

  fem define node;r;block2;example reg 2
  fem define elem;r;block2;example reg 2
  fem def fibre;r;block2;example reg 2
  fem def elem;r;block2;example fibre reg 2

  #fem expor node;master as master reg 2
  #fem expor elem;master as master reg 2

  fem group face 12 as MASTER_FACE reg 2
  fem group face 5 as SLAVE_FACE reg 1

  fem group node 13..16 as FIXED_MASTER reg 2
  fem group node 5..8 as FIXED_SLAVE reg 1

  fem def equa;r;mechanics;example reg 1
  fem def mat;r;mr_slave;example reg 1
  fem def init;r;block1;example reg 1

  fem def equa;r;mechanics;example reg 2
  fem def mat;r;mr_master;example reg 2
  fem def init;r;block2;example reg 2

  fem def solve;r;contact;example coupled reg 1,2

  # Define contact parameters
  fem def contact;r;contact;example

  $CONVERGED=0;
  while ($CONVERGED == 0){

    ### Projection
    &project;

    #################################################################
    # Set $LINESEARCH to 1 so that when line search routines
    # are called inside CMISS, fortran will only read the line search 
    # commands at the beginning of the COM file, and skip the rest.
    #################################################################
    $LINESEARCH=1;

    ### Mechanics problem
    fem solve coupled reg 1,2   

                  } #CONVERGED

  fem def init;w;conv_soln reg 1

} # else $LINESEARCH

Files used by this example are:

Name              Modified     Size

example_5j5.com   30-Aug-2010  3.6k
block1.ipelem     25-Aug-2010  544 
block1.ipelfb     25-Aug-2010  389 
block1.ipfibr     25-Aug-2010  2.1k
block1.ipinit     25-Aug-2010  2.8k
block1.ipnode     25-Aug-2010   14k
block2.ipelem     25-Aug-2010  541 
block2.ipelfb     25-Aug-2010  358 
block2.ipfibr     25-Aug-2010  2.1k
block2.ipinit     25-Aug-2010  2.8k
block2.ipnode     25-Aug-2010   14k
contact.ipcont    25-Aug-2010  627 
contact.ippara    31-Aug-2010  5.9k
contact.irsolv    27-Aug-2010  2.6k
conv_soln.ipinit  25-Aug-2010   42k
mechanics.ipequa  25-Aug-2010  2.2k
mr_master.ipmate  25-Aug-2010  2.8k
mr_slave.ipmate   25-Aug-2010  2.8k
regi.ipregi       25-Aug-2010   93 
tricubic.ipbase   25-Aug-2010  6.6k

Download the entire example:

Name                      Modified     Size

examples_5_5j_5j5.tar.gz  01-Sep-2010   15k

Testing status by version:

Testing status by file:

• cmiss_test.log
  

  x86_64-linux
  Success	cm:	cmiss_test.log.retain.
  Success	cm-debug:	cmiss_test.log.retain.

  
  
• conv_soln.ipinit
  

  x86_64-linux
  Success	cm:	ndiff test: no significant differences with generic answer.
  Success	cm-debug:	ndiff test: no significant differences with generic answer.

  
  

Html last generated: Sun Mar 6 05:50:29 2016

Input last modified: Tue Aug 31 13:19:30 2010