New Method for Generating Strut-and-Tie Models of Three-Dimensional Concrete Anchorage Zones and Box Girders

Abstract

The determination of a suitable strut-and-tie model (STM) of a number of disturbed three-dimensional (3D) domains is a challenging task. To overcome this problem, this paper presents a performance-based ground structure optimization method for automatically generating optimal STMs in 3D concrete structures. In this method, first, a new microtruss element in which each internal node provides equal opportunities for transferring loads is proposed. Then, an equivalence mode between the microtruss element and the continuum element is introduced to ensure a realistic and precise simulation of actual structures. Finally, several examples are used to demonstrate the capability of the proposed approach for revealing the true mechanisms of the load transfer in 3D concrete structures. The numerical results indicate that the developed algorithm can generate optimal STMs that are supported by design specifications and previously existing solutions and can be used in practice, especially in complex disturbed concrete structures for which STMs cannot be obtained by general optimization methods. Generally, the procedure presented in this paper is limited to homogeneous material with linear constitutive laws.