Numerical evaluation of fibre anchor configurations in cfrp-strengthened concrete beams

This study presents a detailed numerical investigation of beams strengthened with CFRP sheets and anchored using splay type fibre systems. Finite element models were developed in ABAQUS and validated against full scale tests with over 95 % accuracy in predicting ultimate load. The models reproduced the load–deflection behaviour and failure modes with high fidelity, supporting the parametric study. For T-section beams, the analysis examined embedment depth, anchor spacing, and end-anchor removal. For rectangular beams, it focused on embedment depth for two web sizes. In T beams, a 100 mm embedment depth prevented pull out and caused CFRP rupture, confirming full tensile mobilisation. An optimal 140 mm spacing maintained effective stress transfer, while wider spacing induced premature debonding. End anchors within 16 % of the shear span contributed negligibly, defining a non-effective anchorage zone. In rectangular beams, capacity plateaued with deeper embedment as early concrete crushing limited the mobilisation of the CFRP. Increasing the web depth from 305 mm to 350 mm produced only a minor capacity increase. These findings demonstrate that beam geometry strongly governs anchor performance and provide guidance for efficient CFRP strengthening design.