Optimal Design of Steel–Concrete Composite Beams Strengthened under Load

This paper presents results of numerical analysis and experimental research on strengthening of steel–concrete composite beams. Studied members consisted of IPE200 I-beam and 90 × 700 mm reinforced concrete slab. The steel part of the section was strengthened by welding additional steel plates at the bottom. The study was performed for plate thickness ranging between 6 to 22 mm. Spatial FEM models were developed to account for material and geometric nonlinearities and for stress and post-welding strain. Proposed numerical models were experimentally validated. One aim was to find an optimum solution which would minimize cost and maximize bending capacity. To achieve this, energy parameters available in numerical simulations were reviewed and analyzed. Recoverable strain energy value determined in Abaqus was used to find the optimum solution.