SAWS
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). |
|
Stiffness ratio of the asymptotic line to the spring element envelope curve. The slope of this line is R1 S0. (0 < R1 < 1.0). |
|
Stiffness ratio of the descending branch of the spring element envelope curve. The slope of this line is R2 S0. ( R2 < 0). |
|
Stiffness ratio of the unloading branch off the spring element envelope curve. The slope of this line is R3 S0. ( R3 1). |
|
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:
Click to download files
Example: Hysteresis

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)