Reverse engineering strut‐and‐tie models for assessing reinforced concrete structures

Abstract Strut‐and‐tie models enable the design of reinforced concrete structures with static or geometrical discontinuities, providing interpretability and control over the load path. These models are valuable for designing discontinuity regions of new structures and for validating nonlinear finite‐element analysis results. However, developing a strut‐and‐tie model for a given geometry and reinforcement layout—as required for the structural assessment of existing structures—is particularly challenging due to time constraints and the need for engineering expertise. This work addresses these issues by proposing a two‐stage method to reverse engineer strut‐and‐tie models and to maximize the load‐bearing capacity based on a given reinforcement layout, geometry, material properties, and proportional load case. The method combines elements of discrete layout optimization, various simplification and sparsification techniques and nonlinear nonconvex geometry optimization to generate simple, interpretable strut‐and‐tie models. Four literature examples demonstrate the suitability of the proposed method across varying levels of complexity and scale. This marks the first steps toward automating the derivation of strut‐and‐tie models for structural assessment, thereby improving efficiency without compromising interpretability and supporting practicing engineers in their daily tasks.