From Carat++ Public Wiki
To beform an analysis for form finding with CARAT++ the related analysis type have to be defined. The following table shows all important commands to define a
form finding analysis in CARAT++. This tabel gives an explanation for each paramter due to that no futher describtion of the paramters will be given.
!<--
Compulsory Parameters
|
Parameter
|
Values, Default(*)
|
Description
|
PC-ANALYSIS <Nr> & * & Analysis with the number <nr>
|
& & the number have to be \tabularnewline
& & followed by : FOMFINDING \tabularnewline
|
DOMAIN & * & Domain which should be calculated \tabularnewline
& & (e.g. EL-DOMAIN 1) \tabularnewline
& & The Parameter EL-DOMAIN should be \tabularnewline
& & defined in the Element \tabularnewline
& & Block of the Inputfile \tabularnewline
\hline
OUTPUT & * & Definition of the Output object \tabularnewline
& & (e.g. PC-OUT 1) \tabularnewline
& & The Parameter PC-OUT 1 should be\tabularnewline
& & defined in the PC-Problem \tabularnewline
& & Block of the Inputfile \tabularnewline
\hline
SOLVER & * & Definition of the Solver object \tabularnewline
& & (e.g. PC-SOLVER 1) \tabularnewline
& & The Parameter PC-SOLVER 1 should be \tabularnewline
& & defined in the PC-Problem \tabularnewline
& & Block of the Inputfile \tabularnewline
\hline
COMPCASE & * & Definition of the Computation Case \tabularnewline
& & (e.g. LD-COM 1) \tabularnewline
& & The Parameter LD-COM 1 should be\tabularnewline
& & defined in the Load \tabularnewline
& & Block of the Inputfile \tabularnewline
\hline
FORMFINDING\_STEP & * & Definition of the number of\tabularnewline
& * & form finding steps \tabularnewline
\hline
MAX\_ITER\_EQUILIBRIUM & * & Maximum of number of equilibrium \tabularnewline
& & iterations before CARAT++ stops the \tabularnewline
& & calculation \tabularnewline
\hline
EQUILIBRIUM\_ACCURACY & * & Equilibrium accuracy \tabularnewline
\hline
STRESS\_ADAPTION & 0 & Defines for which elements the distortion \tabularnewline
& & control is active \tabularnewline
\hline
LAMBDA\_MAX & & Maximum allowable element distortion \tabularnewline
& & in case of stress adaption \tabularnewline
\hline
MUE\_RELAX & & Relaxation of the element distortion \tabularnewline
& & (Values between 0 and 1 are valid) \tabularnewline
\hline
\end{tabular}
- .... No default value for this parameter. Compulsory for a calculation.\\
\clearpage
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For the better understanding of the syntax of this kind of analysis in the following an example of an input block for a \textit{form finding} will be shown.
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 10-6. 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 relaxation of the element distortion control is set to 0.
PC-ANALYSIS 1: FORMFINDING
DOMAIN = EL-DOMAIN 1
OUTPUT = PC-OUT 1
SOLVER = PC-SOLVER 1
COMPCASE = LD-COM 1
FORMFINDING_STEP = 20
MAX_ITER_EQUILIBRIUM = 100
EQUILIBRIUM_ACCURACY = 1e-06
STRESS_ADAPTION = PROP_ID 1
LAMBDA_MAX=1.1
MUE_RELAX=0.0