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Hi forum, I'm trying to calibrate model parameters (PT angle, contrac, dilation and liquefaction parameters) of PDMY material using single element simulation (using quad-UP element). Basic purpose of this calibration is to get reasonable post-liquefaction shear strain (in saturated loose sand, relat...

I am using the latest version of OpemSees (2.1.0) which I downloaded from the website. Also I was following examples in the ucsd OpenSees site.......still I have problem. Is this version different from the vesrion through cvs?

Thanks!

Thanks for your suggestions. When I was initializing the stress conditions, I did match elastic poissons ratios with Ko (i.e., poissons ratio=Ko/1+Ko). Now I tried with uniform stiffness every where, elastic initial stresses look reasonable and also I was able update material stage to elasto-plastic...

Hi there, I am trying to use OpenSees to do dynamic 2D effective analyses to evaulate the performance of a underground structure due to liquefaction induced slope failure. I am using UCSD PDMY materials along with quadUP elements to model soil. Due to the irregular ground surface (compose of peaks a...

Thanks Silvia!

Hi

Any body know how to model a simple pendulum using opensees? I want to model change in period of harmonic motion by varying gravity (g), and keeping the length constant.

I would appreciate any idea.

Thanks.

-Lanka.

Thanks, I calculate C as a factor of critical damping (C= damping ratio*critical damping) to use in the second relationship. The unit of C in second case is kg/s , which is different from that of first case (kg/s/m). How the "C" (i.e tangent) values are related between two relationships? H...

Hi Silvia, I am trying to use viscous material with zero length to represent a damper. I understand from the manual, viscous material can be used to used to construct a uniaxial material object with a non-linear elastic stress-strain-rate relation given by: stress =C(strain-rate)^alpha. My question ...

Hi Robbie

I am using 4 node quad elements, not UP elements.

Thanks.

-Lanka.

Hi, I am using PDMY material (coupled with FluidSolidPorous Material) to simulate saturated, undrained elastic-plastic response of soil. I use 4 node quad elements to model soil. When I try to record pore pressures and pore pressure ratios, I am getting only the time array in the output file. This i...

thanks frank.

Hi Linda,
I believe it should be dry density for the case of dry sand.

-Lanka

Hi Silvia, I recently installed 1.7.5 version of OpenSees. I am getting following warning for updateMaterialStage commad of PDMY material with 1.7.5 version. WARNING: updateMaterialStage - MaterialStageParameter:: setDomain() - no effect with material tag $ID My script worked fine with 1.7.3 version...

Thanks!
Do we have any example shows a dynamic lateral load analysis by applying a force time series? I looked at the example manual all of them are using either uniform eq or multi-support eq.

Thanks! I looked at the examples. I am little bit confused. In all the examples dynamic lateral load is specified as either acceleration (using uniform eq.) or displacement (using multiple support eq.). Its seems some of the commands are unique to the Multiple support excitation or uniform eq. Can't...