Development of an Interactive Web-Based Tool for 2D Truss Analysis Using the Direct Stiffness Method

Abstract

The integration of computational tools in structural engineering education often relies on “black-box” commercial software, which can obscure the fundamental mechanics of the direct stiffness method (DSM) from students. This paper presents the development of the “Professional Truss Suite,” an interactive, web-based application designed to provide a true “glass-box” environment for the analysis of 2D trusses. Built using Python and the Streamlit framework, the tool not only automates the assembly and partitioning of global stiffness matrices but also explicitly exposes the intermediate mathematical steps—including element stiffness matrices, global assembly, and local force extraction—to the user. To enhance model building, explicit node numbering and dynamic unit scaling have been integrated into the graphical overlay. The software's pedagogical efficacy and accuracy were verified through a comprehensive case study of a 9-member Pratt truss under combined loading, yielding results with 0.00% numerical error against theoretical benchmarks. By bridging the gap between manual matrix calculations, stability validation, and professional reporting automation, this tool provides a robust platform for classroom instruction.