SAWS Material: Difference between revisions

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(Imported PYSimple1 to start)
 
(Text Modified - still need to upload files and figures)
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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).
This file contains the class definition for  SAWSMaterial.  SAWSMaterial provides the implementation of a one-dimensional hysteretic model develeped as part of  the CUREe Caltech wood frame project.  
 




{|  
{|  
| style="background:yellow; color:black; width:800px" | '''uniaxialMaterial PySimple1 $matTag $soilType $pult $Y50 $Cd <$c>'''
| style="background:yellow; color:black; width:800px" | '''uniaxialMaterial SAWS $tag $F0 $FI $DU $S0 $R1 $R2 $R3 $R4 $alph $beta'''
|}
|}


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|  style="width:150px" | '''$matTag ''' || integer tag identifying material
|  style="width:150px" | '''$matTag ''' || integer tag identifying material
|-
|-
|  '''$soilType ''' || soilType = 1 Backbone of p-y curve approximates Matlock (1970) soft clay relation.
|  '''$F0 ''' || Intercept strength of the shear wall spring element for the asymtotic line to the envelope curve F0 > FI > 0
 
|-
soilType = 2 Backbone of p-y curve approximates API (1993) sand relation.
|  '''$FI ''' || Intercept strength of the spring element for the pinching branch of the hysteretic
curve. (FI > 0).
|-
|  '''$DU ''' || Spring element displacement at ultimate load. (DU > 0).
|-
|  '''$S0 ''' || Initial stiffness of the shear wall spring element (S0 > 0).
|-
| '''$R1''' || Stiffness ratio of the asymptotic line to the spring element envelope curve. The
slope of this line is R1 S0. (0 < R1 < 1.0).
|-
| '''$R2''' || Stiffness ratio of the descending branch of the spring element envelope curve. The
slope of this line is R2 S0. ( R2 < 0).
|-
|-
| '''$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].
| '''$R3''' || Stiffness ratio of the unloading branch off the spring element envelope curve. The
slope of this line is R3 S0. ( R3  1).
|-
|-
| '''$Y50 ''' || Displacement at which 50% of pult is mobilized in monotonic loading.
| '''$R4''' || Stiffness ratio of the pinching branch for the spring element. The slope of this line
is R4 S0. ( R4 > 0).
|-
|-
| '''$Cd ''' || Variable that sets the drag resistance within a fully-mobilized gap as Cd*pult.
| '''$alpha''' || Stiffness degradation parameter for the shear wall spring element. (ALPHA > 0).
|-
|-
| '''$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
| '''$beta''' || Stiffness degradation parameter for the spring element. (BETA > 0).
|}
|}


NOTES:
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.
Refer to the figure below for more information, and the reference provided at the end of this page for complete details about modeling assumptions.
 
 




[[Image:PySimple1A.gif]]




[[Image:PySimple1B.gif]]
EXAMPLE FILES:


EXAMPLE:




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REFERENCES:  
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.
Reference: Folz, B. and Filiatrault, A. (2001). "SAWS - Version 1.0, A Computer Program for the Seismic Analysis of Woodframe Structures", Structural Systems Research Project Report No. SSRP-2001/09, Dept. of Structural Engineering, UCSD, La Jolla, CA .


----
----


Code Developed by: <span style="color:blue"> Ross Boulanger, UC Davis </span>
Code Developed by: <span style="color:blue"> Patxi Uriz, Exponent </span> (Converted from FORTRAN code originally written by Bryan Folz)

Revision as of 08:10, 21 November 2009

This file contains the class definition for  SAWSMaterial.  SAWSMaterial provides the implementation of a one-dimensional hysteretic model develeped as part of  the CUREe Caltech wood frame project.


uniaxialMaterial SAWS $tag $F0 $FI $DU $S0 $R1 $R2 $R3 $R4 $alph $beta
$matTag integer tag identifying material
$F0 Intercept strength of the shear wall spring element for the asymtotic line to the envelope curve F0 > FI > 0
$FI Intercept strength of the spring element for the pinching branch of the hysteretic

curve. (FI > 0).

$DU Spring element displacement at ultimate load. (DU > 0).
$S0 Initial stiffness of the shear wall spring element (S0 > 0).
$R1 Stiffness ratio of the asymptotic line to the spring element envelope curve. The

slope of this line is R1 S0. (0 < R1 < 1.0).

$R2 Stiffness ratio of the descending branch of the spring element envelope curve. The

slope of this line is R2 S0. ( R2 < 0).

$R3 Stiffness ratio of the unloading branch off the spring element envelope curve. The

slope of this line is R3 S0. ( R3 1).

$R4 Stiffness ratio of the pinching branch for the spring element. The slope of this line

is R4 S0. ( R4 > 0).

$alpha Stiffness degradation parameter for the shear wall spring element. (ALPHA > 0).
$beta Stiffness degradation parameter for the spring element. (BETA > 0).


NOTES:

Refer to the figure below for more information, and the reference provided at the end of this page for complete details about modeling assumptions.




EXAMPLE FILES:



REFERENCES:

Reference: Folz, B. and Filiatrault, A. (2001). "SAWS - Version 1.0, A Computer Program for the Seismic Analysis of Woodframe Structures", Structural Systems Research Project Report No. SSRP-2001/09, Dept. of Structural Engineering, UCSD, La Jolla, CA .

Code Developed by: Patxi Uriz, Exponent (Converted from FORTRAN code originally written by Bryan Folz)

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