KikuchiBearing

This command is used to construct a KikuchiBearing element object, which is defined by two nodes. This element consists of multiple shear spring model (MSS) and multiple normal spring model (MNS).

element KikuchiBearing $eleTag $iNode $jNode
        -shape $shape -size $size $totalRubber
        < -totalHeight $totalHeight >
        -nMSS $nMSS -matMSS $matMSSTag
        < -limDisp $limDisp >
        -nMNS $nMNS -matMNS $matMNSTag 
        < -lambda $lambda > 
        < -orient < $x1 $x2 $x3 > $yp1 $yp2 $yp3 > 
        < -mass $m > 
        < -noPDInput > 
        < -noTilt > 
        < -adjustPDOutput $ci $cj > 
        < -doBalance $limFo $limFi $nIter >

eleTag

unique element object tag

inode jnode

end nodes

shape

following shapes are available: round, square

size

diameter (round shape), length of edge (square shape)

totalRubber

total rubber thickness

totalHeight

total height of the bearing (defaulut: distance between iNode and jNode)

nMSS

number of springs in MSS = nMSS

matMSSTag

matTag for MSS

limDisp

minimum deformation to calculate equivalent coefficient of MSS (see note 1)

nMNS

number of springs in MNS = nMNS*nMNS (for round and square shape)

matMNSTag

matTag for MNS

lambda

parameter to calculate compression modulus distribution on MNS (see note 2)

x1 x2 x3

vector components in global coordinates defining local x-axis

yp1 yp2 yp3

vector components in global coordinates defining vector yp which lies in the local x-y plane for the element

m

element mass

-noPDInput

not consider P-Delta moment

-noTilt

not consider tilt of rigid link

ci cj

P-Delta moment adjustment for reaction force (default: ci=0.5, cj=0.5)

limFo limFi nIter

tolerance of external unbalanced force (limFo), tolorance of internal unbalanced force (limFi), number of iterations to get rid of internal unbalanced force (nIter)

NOTES:

  1. If limdisp is positive and the shear deformation of MSS exceeds limdisp, this element calculates equivalent coefficient to adjust force and stiffness of MSS. The adjusted MSS force and stiffness reproduce the behavior of the previously defined uniaxial material under monotonic loading in every direction.

    1. Recommended value is (D/t)sqrt(3G/K), where D, t, G and K are size (for round and square shape), thickness, shear modulus and bulk modulus of a rubber layer, respectively.

      1. The valid queries to a KikuchiBearing element when creating an ElementRecorder object are ‘globalForce’, ‘localForce’, ‘basicForce’, ‘localDisplacement’ and ‘basicDeformation’.

        KikuchiBearing_Model.png

Examples

element KikuchiBearing 1 1 2 -shape round -size 1.016 0.320 -nMSS 8 -matMSS 1 -nMNS 30 -matMNS 2

KikuchiBearing_Sample.tcl, KikuchiBearing_input_Z.tcl, KikuchiBearing_input_X.tcl

case 1: P-Delta effect not considered (use -noPDInput -noTilt option)

case 2: P-Delta effect considered, uniform distribution of compression modulus

case 3: P-Delta effect considered (use -lambda option)

KikuchiBearing_ForceDeformation_case1_v2.png       KikuchiBearing_ForceDeformation_case2_v2.png       KikuchiBearing_ForceDeformation_case3_v2.png

References

M. Kikuchi , I. D. Aiken and 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

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