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 stuff. One cool thing I've come across is bots that automatically retweet and/or favorite tweets that contain specific … 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 →