Multiobjective Optimization of an Unbiased Model for Externally Bonded CFRP System Contributions to Shear Resistance in RC Beams

Abstract

Predicting the shear resistance of reinforced concrete (RC) beams strengthened with externally bonded reinforcement using carbon fiber–reinforced polymer (CFRP) materials poses a significant challenge due to the complex nonlinear relationship with beam features and the inherent randomness in shear failure events, driven by their brittle nature. This paper proposes a model employing a multiobjective optimization technique that both, enhances the accuracy and ensures unbiased predictions. To highlight the achieved improvement, a comparison is made between the performance of the proposed model and a series of well-established models in the literature. The proposed model presents superior predictive performance and a smaller coefficient of variation in the model error distribution than the models in the literature. In addition, it exhibits unbiased predictions, highlighting the advantages of incorporating multiobjective optimization. Furthermore, a modified demerit point classification is introduced and applied to all models, highlighting the superiority of the proposed model in producing more reliable and cost-effective predictions.