Integrating constructability constraints into an equilibrium-aware grammar for generative structural design

Generating efficient structural forms, such as strut-tie models or reticulated steel structures, significantly relies on optimization methods that yield unique solutions, but with limited control over topology and force distribution. This paper presents a grammar-based workflow to assist architects and structural designers in generating equilibrium structures. The grammar integrates static equilibrium principles and facilitates the exploration of diverse structural design candidates, though not necessarily optimum. The workflow is extended to generate constructible reticulated structures and minimize cutoffs by integrating bar-length constraints simulating realistic conditions. These constraints allow designers to set the length of structural elements-whether struts/ties or bars in tension/compression-within predefined continuous bounded ranges (minimum/maximum), or from a list of predefined lengths, which is prioritized when possible. To validate the workflow, design problems for bar-length constrained structures are presented as proof of concept. Instances of structures lacking such constraints highlight the importance of integrating constraints into the grammar-based generative workflow.