3.1.10.59. TripleFrictionPendulumBearing Element

This command constructs the original triple friction pendulum (TFP) bearing element of Becker and Mahin. It models four sliding interfaces with geometry and friction coefficients specified directly. For the series-model element of Dao et al. see TripleFrictionPendulum Element. For heating effects see TripleFrictionPendulumX Element.

element TFP $eleTag $iNode $jNode $R1 $R2 $R3 $R4 $D1 $D2 $D3 $D4 $d1 $d2 $d3 $d4 $mu1 $mu2 $mu3 $mu4 $h1 $h2 $h3 $h4 $H0 $colLoad <$K>

Argument	Type	Description
$eleTag	integer	unique element tag
$iNode $jNode	integer	end nodes
$R1 $R2 $R3 $R4	float	radii of inner bottom; inner top; outer bottom; outer top sliding surfaces
$D1 $D2 $D3 $D4	float	diameters of inner bottom; inner top; outer bottom; outer top sliding surfaces
$d1 $d2 $d3 $d4	float	diameters of inner bottom; inner top; outer bottom; outer top sliders
$mu1 $mu2 $mu3 $mu4	float	friction coefficients at the four sliding surfaces
$h1 $h2 $h3 $h4	float	heights from each sliding surface to bearing center
$H0	float	total height of bearing
$colLoad	float	initial axial load on bearing (used for first step only)
$K	float	vertical spring stiffness (optional; default 1.0e15)

Note

Valid Element Recorder queries include force, localForce, basicForce, localDisplacement, basicDisplacement, relativeDisp, plasticDisp, and material $matNum ....

Example

1. Tcl Code

element TFP 1 1 2 12.0 12.0 88.0 88.0 12.0 12.0 44.0 44.0 8.0 8.0 12.5 12.5 0.02 0.02 0.09 0.12 3.0 3.0 4.5 4.5 12.5 45.0

2. Python Code

element('TFP', 1, 1, 2, 12.0, 12.0, 88.0, 88.0, 12.0, 12.0, 44.0, 44.0,
        8.0, 8.0, 12.5, 12.5, 0.02, 0.02, 0.09, 0.12, 3.0, 3.0, 4.5, 4.5, 12.5, 45.0)

Code developed by: Tracy Becker, University of California, Berkeley