4.16.14. Isolator2spring Section¶

section('Isolator2spring', matTag, tol, k1, Fyo, k2o, kvo, hb, PE, Po=0.0)

This command is used to construct an Isolator2spring section object, which represents the buckling behavior of an elastomeric bearing for two-dimensional analysis in the lateral and vertical plane. An Isolator2spring section represents the resultant force-deformation behavior of the bearing, and should be used with a zeroLengthSection element. The bearing should be constrained against rotation.

`secTag` (int)	unique section tag
`tol` (float)	tolerance for convergence of the element state. Suggested value: E-12 to E-10. OpenSees will warn if convergence is not achieved, however this usually does not prevent global convergence.
`k1` (float)	initial stiffness for lateral force-deformation
`Fyo` (float)	nominal yield strength for lateral force-deformation
`k2o` (float)	nominal postyield stiffness for lateral force-deformation
`kvo` (float)	nominal stiffness in the vertical direction
`hb` (float)	total height of elastomeric bearing
`PE` (float)	Euler Buckling load for the bearing
`Po` (float)	axial load at which nominal yield strength is achieved (optional)