Abstract
This study examines how perforation layout alters the governing load-transfer mechanism in pretensioned glass fiber-reinforced polymer (GFRP)-reinforced perforated deep beams and how boundary restraint modifies the resulting structural response. Previously reported experimental results were used to validate a nonlinear finite element model against the measured load-displacement response and observed failure pattern of the reference specimens. The validated model was then used to assess perforation placement, alternative hole arrangements, and boundary-restraint conditions. The novelty lies in linking perforation layout and boundary restraint through the load-transfer mechanism: perforation layout controls compression-path continuity, while boundary restraint governs crack redistribution before localized failure. The analyses show that the structural response is governed by the interaction between the perforation pattern and the internal compression stress field. Web perforations interrupt the principal load-transfer path and promote early horizontal shear localization. In contrast, flange perforations preserve a more favorable response, with improved reinforcement utilization and greater deformation capacity. The proposed modified configurations show consistent gains relative to the baseline arrangement, with the best-performing case achieving a 56.4% increase in ultimate load and a 240.9% increase in ultimate displacement. The boundary-condition study further demonstrates that restraint compatibility and plate spacing substantially influence stiffness development, crack propagation, and failure mode.