SAWS Material

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

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$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.

File:FolzFigre.gif

EXAMPLE FILES:

Media:Test.tcl

Media:SAWSZeroLength.tcl

Media:TestHysteresis.jpg

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 .

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