PySimple1 Material

This command is used to construct a uniaxial Kent-Scott-Park concrete material object with degraded linear unloading/reloading stiffness according to the work of Karsan-Jirsa and no tensile strength. (REF: Fedeas).

uniaxialMaterial PySimple1 $matTag $soilType $pult $Y50 $Cd <$c>

---

$matTag	integer tag identifying material
$soilType	soilType = 1 Backbone of p-y curve approximates Matlock (1970) soft clay relation. soilType = 2 Backbone of p-y curve approximates API (1993) sand relation.
$pult	Ultimate capacity of the p-y material. Note that "p" or "pult" are distributed loads [force per length of pile] in common design equations, but are both loads for this uniaxialMaterial [i.e., distributed load times the tributary length of the pile].
$Y50	Displacement at which 50% of pult is mobilized in monotonic loading.
$Cd	Variable that sets the drag resistance within a fully-mobilized gap as Cd*pult.
$c	The viscous damping term (dashpot) on the far-field (elastic) component of the displacement rate (velocity). (optional Default = 0.0). Nonzero c values are used to represent radiation damping effects

NOTES:

In general the HHT algorithm is preferred over a Newmark algorithm when using this material. This is due to the numerical oscillations that can develop with viscous damping forces under transient loading with certain solution algorithms and damping ratios.

File:PySimple1A.pdf

File:PySimple1B.pdf

Typical Hysteretic Stress-Strain Relation for material

EXAMPLE:

REFERENCES:

"Seismic Soil-pile-strcture interaction experiments and analysis", Boulanger, R.w., Curras, C.J., Kutter, B.L., Wilson, D.W., and Abghari, A. (1990). Jornal of Geotechnical and Geoenvironmental Engineering, ASCS, 125(9):750-759.

---

Code Developed by: Ross Boulanger, UC Davis