The OpenSees Community

Hello There: >Is there any version of OpenSees linked >from your home page where these >materials are maintained? No, OpenSees is a UCB product and you need to talk to UCB folks about maintenance of all code... We have a different code, that is in public domain (there is/will be link from my web sit...

you are using small deformation assumption (with current thatold implemenation of u-p-U) so anything you do counts as small deformations. there is an old implementation of u-p finite element and material models for large deformation from us (CompGeoMech at UCD) in OpenSees repository so something al...

Hello There, Just a repeat of an earlier note: small and large deformation material models (von Mises, Drucker Prager, rounder Mohr-Coulomb, Cam Clay, Dafalias Manzari, SaniSand, various hardening rules, ...) in Newtemplate3Dep, Template3Dep and FiniteDeformation directories have not been maintained...

Hello All, just a brief follow up on my impromptu talk on Friday: PDF file for that talk is available here: http://sokocalo.engr.ucdavis.edu/~jeremic/Bib_WWW_Presentations.pdf as #54 (I have used an old talk from last year at CompDyn...). Of possible interest is also a full report describing Plastic...

take a look at: @article {Yang2002a, author = { Zhaohui Yang and Boris Jeremi{\' c} }, title = { Numerical Study of the Effective Stiffness for Pile Groups }, journal = { International Journal for Numerical and Analytical Methods in Geomechanics }, year = { 2003 }, volume = { 27 }, number = { 15 }, ...

Hello Ihsan, I think that we have that output (and others) working, but since our project with OpenSees expired, we now maintain our own source base, used for other projects we work on... Depending on what you do want to model, and since we use part of OpenSees framework, maybe we could help you wit...

It should not be done in 2D! The problem is inherently 3D, as there is flow of fluid and soil skeleton around the piles and other 3D effects... Take a look at last few presentations that I have linked to my web site: http://geomechanics.ucdavis.edu for an idea what ca be done. As for DOFs, you conne...

Sure if it is 4 storry high it might be only marginally better case. Even for a 4 story high wall, there are beams (plates) on each level that bring in normal forces and bending moments and shear forces. So yes the tall wall would have a main (probably) mode of bending along the height (say a very t...

It is quite wrong to model a wall using beam elements. I just finished teaching mechanics of materials and the first thing we cover in going over beams is that the theory covers slender beams, while there is a set of additional terms (also approximate) that take care of shear deformations for beams ...

We have not used Leon model in few years so I am not sure what is going on.It is not part of what we are contracted to do for OpenSees so I am not sure what the status of the code at UCB is. This was a GPL contribution many years ago, but since I stopped doing those a while ago (for various reasons)...

since pore pressure is a DOF you do specifiy it as such (initial displacements...). there is no forcing term for p on the RHS... that equation (8.26) gives conditions for strong form (before discretization), while if you look at equations 8,62 and 8.63, they give you the appropriate forms after deis...

You can do this in a number of ways. 1. Simplest way to do it is to assign anisotropic elasticity, which would them make the elastic-plastic model anisotropicas well (it will "shift" or deform the yield surface in stress space). This is a good solution if you indeed have elastic anisotropy...

Hello There, for u-p-U formulation, each of the nodes has 7DOFs (3 u, 1 p and 3 U) and they behave (almost) the same way as regular DOFs... It is very important to realize that both p and U describe BC for the same pore fliud so they are not independent. So if you specify pore pressure as constraine...

Hello There, You just connect the nodes on the boundary for shear beam effects. However, I would strongly suggest looking into Domain Reduction Method (DRM) for any seismic load application. That method is the only one that is actually dynamically consistent (it is analytic). It is also available th...

take a look at the writeup on DRM in my lecture notes:
http://sokocalo.engr.ucdavis.edu/~jerem ... es_2up.pdf
This includes command explanation...
Boris