Gimme All Your Damping, All Your Mass and Stiffness Too

Just because OpenSees is open source does not mean it is a fully transparent box. This is mostly because documentation has lagged behind development. So, pessimists would say the box is semi-opaque while optimists would characterize it as semi-transparent. But a few parts of OpenSees are definitely housed in an opaque box. Take, for instance, … Continue reading Gimme All Your Damping, All Your Mass and Stiffness Too

Be Careful with Modal Damping

Modal damping is kind of the it-spell in the dark art that is modeling viscous damping in structures. Although modal damping is pretty straightforward, you should be aware of an important aspect of its implementation in OpenSees. The issue is that OpenSees assembles the dynamic tangent in to the matrix storage scheme you choose via … Continue reading Be Careful with Modal Damping