Hysteretic Material

[ms1]

Silvia,

I would like to get a copy of an example that uses the Hysteretic Material, if you will.

Thanks,
MS

[silvia]

here is an excerpt from my materials definition:

Code: Select all

	# back-bone stress-strain curve parameters for all materials
set Fy 		[expr 66.8*$ksi];		# STEEL yield stress
set Es		[expr 29000.*$ksi];	# modulus of steel
set epsY 		[expr $Fy/$Es];		# steel yield strain
set epsSH 	[expr 8*$epsY];		# strain at onset of Strain Hardening
set Esh 		[expr 0.02*$Es];		# tangent stiffness at onset of StrainHardening
set Bs		0.01;			# strain-hardening ratio 
set Fy1		[expr 1.5*$Fy];		# steel stress post-yield
set epsY1		[expr $epsY+($Fy1-$Fy)/($Bs*$Es)];	# steel strain post-yield
#set Fu 		[expr 1.5001*$Fy];		# ultimate stress of steel
#set epsU 	0.25;			# ultimate strain of steel
set Fu 		[expr 1*$Fy];		# ultimate stress of steel# ---------------------------------------------------------------------------
set epsU 		1.0;			# ultimate strain of steel# ---------------------------------------------------------------------------
	# hysteretic-material parameters -- baseline
set pinchX 	1;		# pinching parameter for hysteretic model 
set pinchY 	1;		# pinching parameter for hysteretic model
set damage1 	0.0;		# damage parameter for hysteretic model 
set damage2 	0.0;		# damage parameter for hysteretic model 
set betaMUsteel 	0.0;		# degraded unloading stiffness for hysteretic material based on MU^(-beta)  -- make more like the rest.
	# steel02 and steel03 parameters -- baseline
set R0 18;				# control the transition from elastic to plastic branches -- make more like the rest.
set cR1 0.925;			# control the transition from elastic to plastic branches
set cR2 0.15;			# control the transition from elastic to plastic branches
set a2 0.1; 			# isotropic hardening parameter, associated with a1
set a1 [expr $a2*($Fy/$Es)];		# isotropic hardening parameter, increase of comp. yield envelope as proportion of yield strength after a plastic strain
set a4 0.1; 			# isotropic hardening parameter, associated with a3
set a3 [expr $a4*($Fy/$Es)];		# isotropic hardening parameter, increase of tension yield envelope as proportion of yield strength after a plastic strain 


if {  [info exists imat ] != 1} {set imat 0};		# set value only if it has not been defined previously.
uniaxialMaterial Elastic    	[set IDElastSteel [incr imat 1]] 	$Es;							# elastic reinforcement
uniaxialMaterial Steel01    	[set IDSteel01 [incr imat 1]] 	$Fy      $Es      $Bs;			# bilinear reinforcement
uniaxialMaterial Steel02    	[set IDSteel02 [incr imat 1]] 	$Fy $Es $Bs $R0 $cR1 $cR2
##remove
#uniaxialMaterial Steel02    	[set IDSteel02 [incr imat 1]] 	$Fy $Es [expr -5*$Bs] 22 $cR1 $cR2
## remove
#set eta 0.25
#uniaxialMaterial ElasticPPGap [set IDSteel02 [incr imat 1]] $Es $Fy $epsY1 $eta 100

uniaxialMaterial Steel03    	[set IDSteel03 [incr imat 1]] 	$Fy $Es $Bs $R0 $cR1 $cR2
uniaxialMaterial ReinforcingSteel [set IDReinforcingSteel  [incr imat 1]] 	 $Fy      $Fy1 $Es $Esh $epsSH $epsY1
uniaxialMaterial Hysteretic 	[set IDHysteretic [incr imat 1]] 	$Fy $epsY $Fy1 $epsY1 $Fu $epsU -$Fy -$epsY -$Fy1 -$epsY1 -$Fu -$epsU $pinchX $pinchY $damage1 $damage2 $betaMUsteel ; # hysteritic reinforcemnet model

[edu1]

Hi

A command is used to construct a uniaxial bilinear hysteretic material object with pinching of force and deformation, damage due to ductility and energy, and degraded unloading stiffness based on ductility.

[NerdKid]

Thanks for the excerpt silvia. It will help me much.

[meopensees]

Hi everyone.
i want to model rebar by the use of hystertic material , but unfotunately i have little information about this kind of material.i don't know how to calculate pinchX or another parameters.can you help me and introduce an article about it?

[IsmBaha]

Hello Silvia,
Could you direct us for understanding the material parameters "pinchX pinchY damage1 damage2 beta" of the hysteretic model for concrete reinforcement?
Thank you,
Baha

[salari]

Dear Silvia,
I am getting this error:
Want: uniaxialMaterial Hysteretic tag? mom1p? rot1p? mom2p? rot2p? <mom3p? rot3p?>
mom1n? rot1n? mom2n? rot2n? <mom3n? rot3n?> pinchX? pinchY? damfc1? damfc2? <beta?>
while executing this command:
uniaxialMaterial Hysteretic 1 2.764e+03 2.516e-02 2.764e+03 1.583e-01 8.419e-03 4.700e-01 -2.764e+03 -2.516e-02 -2.764e+03 -1.583e-01 -8.419e-03 -4.700e-01 0.000e+00 0.000e+00 0.000e+00 0.000e+00 8.000e-01
I need to model a steel structure for pushover analysis, I am using OpenSees 2.4.6 for Win7.
How could I model a steel structure with uniaxialMaterial Hysteretic?

Thank you so much

With my kind regards

[fmk]

what version and what os are you using

[ashf]

hello
how can i get value of this parameters???
please help...
thanks

[victoryJCC]

Thanks alot, you save my time today