Design Approach for a Post-Tensioned Funicular Concrete Beam (2024-08)¶

This work proposes an approach to design a structural beam with minimal material by linking the geometric form-finding method, graphic statics, with post-tensioning as well as implementing periodic anticlastic surface geometries. To determine the placement of materials, the methodology extends upon the form-finding method developed in prior work by incorporating volumetric modeling of spatial concrete geometries to increase structural stiffness while also minimizing the overall required mass to achieve the desired performance. The combined compression and tension funicular load paths optimized from graphic statics inform the placement of the post-tensioning reinforcement and the required force to eliminate tensile forces for a given applied load and place the overall structure in compression, engaging the embedded spatial concrete geometries. To further minimize material usage and to integrate the complex spatial geometries, the beam is designed such that it can be concrete 3D-printed, eliminating the need for form-work, which is a significant contributor to construction waste.