In OpenSees, can force-based element(forces are the variables, the equations are based on flexibility matrix ) adopt explicit material model (to describe the stress-strain relationship, strain is variable, stress is the function of strain)?
For example, define one material using steel02, then define one element using "nonlinearbeamcolumn". The script are shown as follows:
##model builder
model BasicBuilder -ndm 2 -ndf 3;
##node
node 1 0.0 0.0;
node 2 100.0 0.0;
## Mass
mass 3 1.0 0.0 0.0;
#Boundary Conditions
fix 1 1 1 1;
fix 2 0 1 1;
## Materials
#uniaxialMaterial Steel02 $matTag $Fy $E $b $R0 $cR1 $cR2 <$a1 $a2 $a3 $a4 $sigInit>
uniaxialMaterial Steel02 1 40.2 29800.0 0.003 20 0.925 0.15 0.0005 0.01 0.0005 0.01;
# reinforcing steel Material
#uniaxialMaterial ReinforcingSteel 1 68.2 102.3 29007 870.2 0.00235 0.0415 -GABuck 11 1.0 0.4 0.5
## Pipe Section (4" diameter, ?" wall thickness)
section Fiber 1 {
patch circ 1 20 4 0.0 0.0 1.5 2.0 0.0 360.0;
}
## Transformation
geomTransf Corotational 1;
## Define Model
#element nonlinearBeamColumn $eleTag $iNode $jNode $numIntgrPts $secTag $transfTag
element nonlinearBeamColumn 1 1 2 3 1 1 ;# Brace
## Recorder
recorder Node -file Rst/LoadDisp.out -time -node 3 -dof 1 disp;
## Apply the nodal Load
pattern Plain 1 Linear { load 2 1.0 0.0 0.0; }
## Static Analysis parameters-force based element
constraints Plain;
numberer RCM;
system UmfPack;
test EnergyIncr 1.0e-8 300 0;
algorithm KrylovNewton;
set peaks [ list 0.25 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 ];
for {set i 1 } { $i <= 9 } {incr i } {
set dU [expr -1.0*pow((-1.0),$i)*[lindex $peaks [expr $i-1] ]/50.0 ];
integrator DisplacementControl 2 1 $dU 1 $dU $dU;
analysis Static;
analyze 50;
}
analysis Static;
analyze 50;
puts "Analysis Completed!"
wipe all;
force-based element adopts explicit material model
Moderators: silvia, selimgunay, Moderators
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- Location: Roma Tre University
force-based element adopts explicit material model
Department of structures
Rome Tre University
Rome Tre University
Re: force-based element adopts explicit material model
Yes. You should read papers, documentation, and examples about the element first.