Welcome to the September 2026 edition of OpenSees Digital Digest, a monthly summary of content published at OpenSees Digital. I'm getting back to more frequent posts: A Minimal OpenSees Model Viewer - Shows how to build a simple 3D OpenSees model viewer with only a couple dozen lines of Python. How to Conquer OpenSees - … Continue reading OpenSees Digital Digest – September 2026
Category: Community
OpenSees Digital Digest – August 2026
Welcome to the August 2026 edition of OpenSees Digital Digest, a monthly summary of content published at OpenSees Digital. I've been on the road a bit this month, but squeaked out one post: Break Your Concentration - Shows how to model concentrated plasticity in OpenSees without using zero length elements. I also started to solve … Continue reading OpenSees Digital Digest – August 2026
OpenSees Digital Digest – July 2026
Welcome to the July 2026 edition of OpenSees Digital Digest, a monthly summary of content published at OpenSees Digital. Verification posts continued this month, as I remain motivated to show OpenSees can be used far beyond simulating the nonlinear seismic response of structural and geotechnical systems. Buoyed by OpenSees - Shows that the PFEM implementation … Continue reading OpenSees Digital Digest – July 2026
OpenSees Digital Digest – June 2026
Welcome to the June 2026 edition of OpenSees Digital Digest, a monthly summary of content published at OpenSees Digital. Verification and correctness of structural analyses continue as recurring themes this month. Something They Can Agree On - Demonstrates one of the few cases where displacement-based and force-based elements give the same material nonlinear flexural response. … Continue reading OpenSees Digital Digest – June 2026
OpenSees Digital Digest – May 2026
Welcome to the May 2026 edition of OpenSees Digital Digest, a monthly summary of content published at OpenSees Digital. The unofficial theme for this month has been verification, ranging from fundamental benchmark problems to workflows that automate verification across larger problem sets. Insert Assertion Here - Demonstrates how assertions can be applied to more than … Continue reading OpenSees Digital Digest – May 2026
Correctness Over Time
Whether it's numerical or epistemic, nonlinear structural analysis is all about minimizing error. While posts glazing Bull Durham will never change, the technical posts on this site start to drift over time. Sometimes it's a change in OpenSees, or I find a better way to show something. Although the blog has gained wide distribution in … Continue reading Correctness Over Time
Ways to Analyze This
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
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