Generating optimal strut-and-tie models in prestressed concrete beams by performance-based optimization

Abstract

This paper deals with automatic generation of optimal strut-and-tie models in prestressed concrete beams by the performance-based optimization (PBO) method. In the present approach, developing strut-and-tie models in prestressed concrete members is transformed to the topology optimization problem of continuum structures. By treating prestressing forces as external loads, prestressed concrete beams can be analyzed, optimized, and dimensioned with strut-and-tie models like reinforced concrete beams. Optimal strut-and-tie models in nonprestressed, partially prestressed, and fully prestressed concrete beams are investigated by using the performance-based optimization technique. It is demonstrated that the magnitude of prestressing farces significantly affects the layouts of optimal strut-and-tie models in prestressed concrete members. The performance-based optimization method is shown to be effective in developing reliable strut-and-tie models for the design of prestressed concrete beams.