Users:Form Finding/Form Finding with CARAT++

From Carat++ Public Wiki
(Difference between revisions)
Jump to: navigation, search
(Example of an Input Block)
Line 63: Line 63:
 
=== Example of an Input Block ===
 
=== Example of an Input Block ===
  
The below shown input block defines a formfinding analysis with the ID 1. It uses for the element domain, the output, the solver and the compcase fields which have the ID 1. The analysis perform 20 formfinding steps and stops the computation after 100 steps if no convergence is reached. The accuracy of the analysis is defined as 10<sup>-6</sup>. Distortion control is enabled and used for elements releated to the elemnt properties with ID 1. The maximum allowed element distortion is 1.1 and relaxation of the element distortion control is set to 0.  
+
The input block shown below defines a formfinding analysis with the ID 1. The analysis performs 10 formfinding steps and stops the computation after 100 equilibrium iteration steps within each formfinding step if no convergence is achieved. The equilibrium accuracy of the analysis is defined as 10<sup>-6</sup>.
  
 +
Distortion control is enabled and used for elements releated to the elemnt properties with ID 1. The maximum allowed element distortion is 1.1 and the relaxation of the element distortion control is set to 0.
 +
For a detailed discussion of the element distortion control see e.g. to <ref name=Lin2009">Linhard, J.: Numerisch-mechanische Betrachtung des Entwurfsprozesses von Membrantragwerken, Lehrstuhl für Statik, Technische Universität München, 2009</ref>
 +
and <ref name="Die14">Dieringer, F.: Numerical Methods for the Design and Analysis of Tensile Structures, Lehrstuhl für Statik, Technische Universität München, 2014</ref>.
 +
 +
== References ==
 +
 +
<references/>
  
 
<pre>
 
<pre>
Line 79: Line 86:
 
   MUE_RELAX=0.0
 
   MUE_RELAX=0.0
 
</pre>
 
</pre>
 +
 +
== References ==
 +
 +
</references>

Revision as of 08:11, 13 January 2017

The following table shows the important commands to define a form finding analysis in CARAT++ and gives an explanation for each parameter.

Compulsory Parameters
Parameter Values Description
PC-ANALYSIS int Analysis with the number int the number have to be followed by : FORMFINDING
DOMAIN EL-DOMAIN int Domain which should be calculated. The parameter EL-DOMAIN should be defined in the Element Block of the Inputfile
OUTPUT PC-OUT int Definition of the Output object. The Parameter PC-OUT should be defined in the PC-Problem Block of the Inputfile
SOLVER PC-SOLVER int Definition of the Solver object. The Parameter PC-SOLVER should be defined in the PC-Problem Block of the Inputfile
COMPCASE LD-COM int Definition of the Computation Case. The Parameter LD-COM should defined in the Load-Block of the Inputfile
FORMFINDING_STEP int Definition of the number of form finding steps
MAX_ITER_EQUILIBRIUM int Maximum of number of equilibrium iterations before CARAT++ stops the calculation
EQUILIBRIUM_ACCURACY real Equilibrium accuracy
FORMFINDING_ELEMENTS PROP_ID ints elements that have to be formfound (i.e. that have no material contribution, but only geometrical stiffness), identified through their property ID
Optional Parameters
STRESS_ADAPTION PROP_ID ints Defines for which elements the distortion control is active through their property ID
LAMBDA_MAX real Maximum allowable element distortion in case of stress adaption
MUE_RELAX real Relaxation of the element distortion (Values between 0 and 1 are valid)

For the better understanding of the syntax of this kind of analysis in the following an example of an input block for a form finding will be shown.

Example of an Input Block

The input block shown below defines a formfinding analysis with the ID 1. The analysis performs 10 formfinding steps and stops the computation after 100 equilibrium iteration steps within each formfinding step if no convergence is achieved. The equilibrium accuracy of the analysis is defined as 10-6.

Distortion control is enabled and used for elements releated to the elemnt properties with ID 1. The maximum allowed element distortion is 1.1 and the relaxation of the element distortion control is set to 0. For a detailed discussion of the element distortion control see e.g. to [1] and [2].

References

  1. Linhard, J.: Numerisch-mechanische Betrachtung des Entwurfsprozesses von Membrantragwerken, Lehrstuhl für Statik, Technische Universität München, 2009
  2. Dieringer, F.: Numerical Methods for the Design and Analysis of Tensile Structures, Lehrstuhl für Statik, Technische Universität München, 2014
PC-ANALYSIS 1: FORMFINDING
  DOMAIN = EL-DOMAIN 1
  OUTPUT = PC-OUT 1
  SOLVER = PC-SOLVER 1
  COMPCASE = LD-COM 1
  FORMFINDING_STEP = 10
  MAX_ITER_EQUILIBRIUM = 100
  EQUILIBRIUM_ACCURACY = 1e-06
  STRESS_ADAPTION = PROP_ID 1
  LAMBDA_MAX=1.1
  MUE_RELAX=0.0

References

</references>





Whos here now:   Members 0   Guests 0   Bots & Crawlers 1
 
Personal tools
Content for Developers