Development of Strut-and-Tie Models Using Load Path in Structural Concrete

Abstract

Strut-and-tie modeling (STM) is widely used in the design of discontinuity regions (D-regions) in structural concrete, but can be hampered by hand-based and experience-dependent problems in the construction of the model. Inspired by the conceptual load-path method, this paper presents the theoretical background and algorithms for automatically generating strut-and-tie models from loads paths in two-dimensional (2D) members. In the proposed approach, the stress field in a concrete continuum is transformed first into load paths, and then the curved load paths are converted into strut-and-tie models. Through the definition of the load path and the formulation of its analytical features, the gap between the stress field and the idealized truss is bridged. Algorithms are programmed in a general-purpose finite-element package to enable convenient applications. Worked examples demonstrate that the proposed approach is qualified for the automatic generation and solving of strut-and-tie models in typical D-regions.