OpenSees is pretty well known for its fiber sections. Although fiber sections are not unique to OpenSees, where else can you choose from 23 uniaxial concrete models and 18 uniaxial steel models to define a reinforced concrete section? There's also a handful of multiaxial material models that capture the interaction of axial and shear stresses … Continue reading The Fiber Content of OpenSees
Category: OpenSees
OpenSees Twitter Bot
Twitter fascinates me. Not only because it's a platform where many academics disseminate the latest additions to their CVs, but also because it has an Application Programming Interface (API) through which you can automate all kinds of cool stuff. One cool thing I've come across is bots that automatically retweet and/or favorite tweets that contain … Continue reading OpenSees Twitter Bot
OpenSees Shells by the Seashore
Other than state-of-the-art material and geometrically nonlinear frame element formulations, it's fair to say OpenSees is not known for its breadth of structural finite elements like quads, bricks, and shells. There are solid elements for geotechnical applications and fluid elements for fluid-structure interaction via the PFEM, but what's the story on shell elements in OpenSees? … Continue reading OpenSees Shells by the Seashore
Unretiring the String Class
If you've compiled the OpenSees source code, you may have noticed the SRC/string directory, whose two files, G3string.h and G3string.cpp, implement character strings as first-class objects, complete with overloaded operators and deep copies. G3string is based on the String class, which I used for programming projects in my undergraduate computer science courses. In the G3string.h … Continue reading Unretiring the String Class
An Update of the IMK Models
Hysteretic models include several parameters that can be fit to a variety of physical phenomena known to occur in steel and reinforced concrete members under cyclic loading. I did my Ph.D. in the Bay Area, but not at The Farm. Accordingly, I'm more of a fiber section aficionado--but I get the appeal of hysteretic models. … Continue reading An Update of the IMK Models
Algorithmic Limerick
There once was a post-doc named Dave,Who ran OpenSees in his cave.Non-convergence, 'bout to miss dinner,He switched the algorithm to 'Linear'.Just think of all the trouble he saved. Although I changed the name and circumstances to protect the guilty, I have known more than one person who, when faced with convergence problems in OpenSees, decided … Continue reading Algorithmic Limerick
Thankful for OpenSees
Thanksgiving is this week, which means campuses across the US will be pretty quiet. Monday through Wednesday should be a boon for faculty seeking "big blocks of time" to write. Let's hope they feel inspired. Come Thursday, we'll reflect on what we're thankful for. Family, friends, and health are perennial list toppers for me. In … Continue reading Thankful for OpenSees
