عنوان مقاله [English]
In the last two decades, strut-and-tie model (STM) has been the most widely used method for design of reinforced concrete disturbed regions. Continuum topology optimization is the latest method for determining appropriate STM. This method does not have limitations of conventional methods.In this article, an efficient methodology is presented for development of STM for reinforced concrete members under multiple loading conditions. Solid isotropic material with penalization (SIMP) topology optimization algorithm is employed to minimize elastic strain energy of the models. In order to prevent checkerboard patterns and mesh dependency, the sensitivity filtering was applied and design variables were updated using the optimality criteria.Two numerical examples were used to investigate the effectiveness of the proposed methodology. The first example is a shear wall with asymmetric opening under reversed static loading. The ultimate load to steel weight ratio was used as the criteria to compare the models with different volume fractions. CAST software was used for analysis and design of models. Nonlinear Finite Element models were developed to obtain load-deflection curves for different models.In the second example, a new criterion was used to compare the STM of a corbel under horizontal and vertical static loads. Effects of different filtering radii were also investigated. The results of this example show that models obtained from topology optimization are efficient and require the minimal steel reinforcement when compared with conventional models. The results indicate that a volume fraction in the range of 0.35-0.45 leads to efficient and optimum models. A low filtering radius results in models with redundant members and a high filtering radius results in removal of members from model. It should be noted that using topology optimization under multiple loads also results in saving the CPU time for analysis and design.