A previous post challenged readers to analyze a simple frame model subjected to static loads. The model had material nonlinearity via tension-only diagonal cables and geometric nonlinearity via the P-Δ effects in the columns. The Challenge Despite these rather simple nonlinearities, analysis of the frame for the given vertical and lateral loads will fail using the default analysis options … Continue reading Ways to Analyze This
Category: Community
Evergreen OpenSees Content
Over six years in and 430 posts down, the blog is moving along in various directions--perhaps orthogonal to previous directions, which is not a bad thing. But what are those previous directions? To help answer that question, I compiled a list of the 30 most read posts over the blog's lifetime. All but one of … Continue reading Evergreen OpenSees Content
Analyze This
I have posted modeling challenges where I describe a model and loading then ask for a specific response quantity. Usually, the model is linear-elastic, e.g., strongback frame, Ziemian frame, and soil-bridge SSI, so the challenge is building the model and the ensuing analysis is straightforward. But what if I gave you an already built model, described the loading, … Continue reading Analyze This
The Maximal Broken Example
When I ask for a minimal working example, I often receive responses that are the opposite of minimal and working, i.e., maximal or broken, in some cases reaching new lows. The following situations can be categorized as MBEs (maximal broken examples), i.e., not a minimal working example. 1. An Example from Your Journal Article I … Continue reading The Maximal Broken Example
Show Me Don’t Tell Me
If there's one thing this blog excels at, it's simple, minimal examples. Yeah, sometimes too minimal and other times too simple--or both. But, when I have a problem with OpenSees, I make a minimal example to be sure I understand the issue. Usually, the issue is me, not OpenSees. You say OpenSeesPy is 2-3 times … Continue reading Show Me Don’t Tell Me
Will OpenSees Ever Be Un-Seen?
OpenSees contains sophisticated solution algorithms and element and constitutive models for simulating the nonlinear response of structural and geotechnical systems to natural and human-made hazards. But sometimes these sophisticated models are put to less than sophisticated use. I've been kicking this idea around in my head for a while, but what xykademiqz wrote in a … Continue reading Will OpenSees Ever Be Un-Seen?
Will Write for OpenSees
Will Write for Food, a popular book in the food blogging world, is a play on the canonical "Will Work for Food" signs that panhandlers display at busy intersections. Although the food blogging world is over saturated, the OpenSees blogging world is not. Will I OpenSees for food? The answer to that question is open … Continue reading Will Write for OpenSees
OpenSees Smarter, Not Harder
Having established the use of OpenSees as a verb, you knew adverbs that describe how one OpenSeeses wouldn't be far behind. For example: How did it go today?I OpenSeesed slowly. I had planned to build a frame model but got distracted by kitten videos. How was the workshop?It was good. I learned some useful tips … Continue reading OpenSees Smarter, Not Harder
OpenSees Pareto Principles
The Pareto Principle, aka the "80/20 Rule", states that 80% of the output is generated by 20% of the input. For example, in any given academic department of engineering, 20% of the faculty generates 80% of the papers, research funding, graduated students, citations, or whatever metric. And 100% of the faculty will tell you they … Continue reading OpenSees Pareto Principles
El viejo y los mares abiertos
Although most of the posts in this blog are about OpenSees, the blog is not affiliated with UC Berkeley, who retains the copyright to OpenSees. Because it is free to use for research and education, some people feel they can do whatever they want with OpenSees, even for commercial purposes, despite an easy to understand … Continue reading El viejo y los mares abiertos
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