KikuchiAikenLRB Material: Difference between revisions

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(Created page with '{{CommandManualMenu}} This command is used to construct a uniaxial KikuchiAikenLRB material object. This material model produces nonlinear hysteretic curves of lead-rubber beari...')
 
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|  '''$hr ''' || total thickness of rubber '''[unit: m]'''
|  '''$hr ''' || total thickness of rubber '''[unit: m]'''
|-
|-
|  '''$gr ''' ||
|  '''$gr ''' || shear modulus of rubber '''[unit: N/m^2]'''
|-
|-
|  '''$ap ''' || area of lead plug '''[unit: m^2]'''
|  '''$ap ''' || area of lead plug '''[unit: m^2]'''
|-
|-
|  '''$tp ''' ||
|  '''$tp ''' || yield stress of lead plug '''[unit: N/m^2]'''
|-
|-
|  '''$alph ''' ||
|  '''$alph ''' || shear modulus of lead plug '''[unit: N/m^2]'''
|-
|-
|  '''$beta ''' ||
|  '''$beta ''' || ratio of initial stiffness to yielding stiffness
|-
|-
|  '''$temp ''' ||
|  '''$temp ''' || temperature '''[unit: °C]'''
|-
|-
|  ''' $rk $rq ''' ||
|  ''' $rk $rq ''' || reduction rate for yielding stiffness ('''$rk''') and force at zero displacement ('''$rq''')
|-
|-
|  '''$rs $rf''' || reduction rate for stiffness ('''$rs''') and force ('''$rf''') (see note 3)
|  '''$rs $rf''' || reduction rate for stiffness ('''$rs''') and force ('''$rf''') (see note 3)
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{|
{|
|-
|-
|  '''1''' || lead-rubber bearing
|  '''1''' || lead-rubber bearing, up to 400% shear strain [Kikuchi et al., 2010 & 2012]
|}
|}


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3) '''$rs''' and '''$rf''' are available if this material is applied to multipleShearSpring (MSS) element.
3) '''$rs''' and '''$rf''' are available if this material is applied to multipleShearSpring (MSS) element.
Recommended values are '''$rs'''=1/sum(i=0,n-1){ sin(n*i/pi)^2} and '''$rf'''=1/sum(i=0,n-1){sin(n*i/pi)},
Recommended values are '''$rs'''=1/sum(i=0,n-1){ sin(pi*i/n)^2} and '''$rf'''=1/sum(i=0,n-1){sin(pi*i/n)},
where n is the number of springs in the MSS.
where n is the number of springs in the MSS.
For example, when n=8, $rs=0.2500 and $rf=0.1989.
For example, when n=8, $rs=0.2500 and $rf=0.1989.
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[[Image:KikuchiAikenLRB_ForceStrain.png|300px]]
[[Image:KikuchiAikenLRB_ForceStrain.png|300px]]
REFERENCES:
M. Kikuchi, T. Nakamura, I. D. Aiken, "Three-dimensional analysis for square seismic isolation bearings under large shear deformations and high axial loads", ''Earthquake Engineering and Structural Dynamics'', Vol. 39, 1513-1531, 2010.
M. Kikuchi , I. D. Aiken, A. Kasalanati , "Simulation analysis for the ultimate behavior of full-scale lead-rubber seismic isolation bearings", ''15th World Conference on Earthquake Engineering'', No. 1688, 2012.
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Code Developed by: <span style="color:blue"> mkiku </span>

Latest revision as of 17:46, 13 March 2018




This command is used to construct a uniaxial KikuchiAikenLRB material object. This material model produces nonlinear hysteretic curves of lead-rubber bearings.

uniaxialMaterial KikuchiAikenLRB $matTag $type $ar $hr $gr $ap $tp $alph $beta <-T $temp> <-coKQ $rk $rq> <-coMSS $rs $rf>

$matTag integer tag identifying material
$type rubber type (see note 1)
$ar area of rubber [unit: m^2]
$hr total thickness of rubber [unit: m]
$gr shear modulus of rubber [unit: N/m^2]
$ap area of lead plug [unit: m^2]
$tp yield stress of lead plug [unit: N/m^2]
$alph shear modulus of lead plug [unit: N/m^2]
$beta ratio of initial stiffness to yielding stiffness
$temp temperature [unit: °C]
$rk $rq reduction rate for yielding stiffness ($rk) and force at zero displacement ($rq)
$rs $rf reduction rate for stiffness ($rs) and force ($rf) (see note 3)

NOTES:

1) Following rubber types for $type are available:

1 lead-rubber bearing, up to 400% shear strain [Kikuchi et al., 2010 & 2012]

2) This material uses SI unit in calculation formula. Input arguments must be converted into [m], [m^2], [N/m^2].

3) $rs and $rf are available if this material is applied to multipleShearSpring (MSS) element. Recommended values are $rs=1/sum(i=0,n-1){ sin(pi*i/n)^2} and $rf=1/sum(i=0,n-1){sin(pi*i/n)}, where n is the number of springs in the MSS. For example, when n=8, $rs=0.2500 and $rf=0.1989.


EXAMPLE:

KikuchiAikenLRB_sample.tcl


REFERENCES:

M. Kikuchi, T. Nakamura, I. D. Aiken, "Three-dimensional analysis for square seismic isolation bearings under large shear deformations and high axial loads", Earthquake Engineering and Structural Dynamics, Vol. 39, 1513-1531, 2010.

M. Kikuchi , I. D. Aiken, A. Kasalanati , "Simulation analysis for the ultimate behavior of full-scale lead-rubber seismic isolation bearings", 15th World Conference on Earthquake Engineering, No. 1688, 2012.


Code Developed by: mkiku