Experimental studies and non-linear finite element analysis of flexural behavior of steel fibre-reinforced concrete under monotonic and repeated cyclic loading

Experimental studies were carried out on beams of size 150 mm × 150 mm × 550 mm, subjected to four-point bending under monotonic and repeated cyclic loading. Hooked-end steel fibres of aspect ratio 50 (50 mm length and 1 mm diameter), at fibre volume fractions—1.0, 1.25, 1.5 and 1.75% for concrete of grade M20 was considered for the study. The load-deflection, moment-curvature and toughness responses were arrived through the tests. Non-linear Finite Element (FE) analysis was carried out for all the tested SFRC beams which were modelled and analyzed using robust and reliable FE tool ANSYS Mechanical APDL 2022 R2. The load-deflection responses arrived through FE analysis were compared and validated with the experimental results. Further the moment-curvature response shown was found to be influenced by the random distribution of steel fibres. This aspect considerably influenced the moment-curvature response under repeated cyclic loading. The ultimate load in flexure was found to be 122%, 133%, 156% and 183% higher for fibre volume fractions of 1.0, 1.25, 1.5 and 1.75%, respectively. Also, the toughness measured was found to be higher by 1993%, 2072%, 1748% and 1833% for fibre volume fractions of 1.0, 1.25, 1.5 and 1.75%, respectively when compared to the plain concrete under monotonic loading. The non-linear FE analysis of SFRC beams were found to be reliable for analyzing the flexural behavior of SFRC members.