Maxwell Material: Difference between revisions

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| '''''1. Input parameters:'''''
| '''''1. Input parameters:'''''
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| Assume a viscous damper with axial stiffness K=150.0kN/mm, viscous parameter C = 100.0kN/(mm/s)^a, an exponent a=0.3 and length equal to 5000mm.  
| Assume a viscous damper with axial stiffness K=150.0kN/mm, viscous parameter <math>C = 100.0kN/(mm/s)^0.3</math>, an exponent a=0.3 and length equal to 5000mm.  
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| The input parameters for the material should be as follows:
| The input parameters for the material should be as follows:

Revision as of 18:02, 15 February 2011




This command is used to construct a Maxwell material (linear spring and nonlinear dashpot in series). The Maxwell material simulates the hysteretic response of viscous dampers.

uniaxialMaterial Maxwell $matTag $K $C $a $L

$matTag integer tag identifying material
$K Elastic stiffness of linear spring (to model elastic stiffness of viscous damper)
$C Viscous parameter of damper
$a Viscous damper exponent
$L Viscous damper length

Examples:

1. Input parameters:
Assume a viscous damper with axial stiffness K=150.0kN/mm, viscous parameter <math>C = 100.0kN/(mm/s)^0.3</math>, an exponent a=0.3 and length equal to 5000mm.
The input parameters for the material should be as follows:
uniaxialMaterial Maxwell 1 150.0 100.0 0.30 5000.0
2. Tcl input file for Viscous Damper Calibration:
3. OpenSees Example of 1-story steel moment frame with a viscous damper:

References:

[1] Olsson, A.K., and Austrell, P-E., (2001), "A fitting procedure for viscoelastic-elastoplastic material models," Proceedings of the Second European Conference on Constitutive Models for Rubber, Germany, 2001.
[2] Ottosen, N.S., and Ristinmaa, M., (1999). "The mechanics of constitutive modelling, (Numerical and thermodynamical topics)," Lund University,Division of Solid Mechanics, Sweden, 1999.

Code Developed by : by Dr. Dimitrios G. Lignos (McGill University)