Reduce Your Bandwidth

For large structural models, the solution to $latex {\bf K}_T\Delta {\bf U}={\bf R}$ can be the computational bottleneck during an analysis. Although computing speed and algorithms to solve $latex {\bf K}_T\Delta {\bf U}={\bf R}$ are very good, you still want to make sure the solution happens as quickly as possible, particularly when inside the double … Continue reading Reduce Your Bandwidth

Rigid Joint Offsets

The geometric coordinate transformation objects handle rigid joint offsets for frame elements in OpenSees. This is nice because the code for the transformations of displacements and forces is not duplicated in the element state determinations. There are three things to keep in mind when using rigid joint offsets. First, the offsets are global with respect … Continue reading Rigid Joint Offsets

Fibers of Higher Dimensions

When we talk about fiber sections in OpenSees, we often refer to Bernoulli sections where each fiber is in a state of uniaxial stress. This approach captures axial-moment interaction, which is important for reinforced concrete columns, whose cross-sections are defined using patch and layer commands. Those same patch and layer commands can be used for … Continue reading Fibers of Higher Dimensions

You Know You’ll Have to Write About It

The odds are, if you're running OpenSees analyses, you're going to write about it, whether it's a thesis/dissertation, technical report, funding proposal, conference paper, or journal article. Several writing books are available and some are very good. One book that I've found useful is Becoming an Academic Writer by Patricia Goodson. The title may sound … Continue reading You Know You’ll Have to Write About It