Çentikli kompozit yapıların bölgesel güçlendirme optimizasyonu ile mekanik özelliklerin iyileştirilmesi

A composite structure is gravely weakened if a cutout is needed for functional purposes. Instead of uniformly increasing the thickness of the whole structure, locally reinforcing the region around the notches is a much more effective way of increasing the load-bearing capacity of a notched structure. The objective of this study is to find the optimum design of reinforcing layers placed around the hole in a composite laminated plate to maximize its ultimate strength with minimum use of reinforcing material. The ultimate failure load is determined using a progressive damage model based on the Puck failure criterion and the material property degradation method. Finite element (FE) models are developed to obtain the structural response of the plate under tension, compression, or pin loading. The optimum local reinforcement design is found using a modified simulated annealing algorithm, which is a reliable stochastic global search algorithm. A multi-objective optimization scheme is adopted, in which the objective function includes both the ultimate strength and the reinforcement weight so that the ultimate strength can be maximized with minimum use of material. The optimization variables are chosen as the fiber-orientation angles and the size of the reinforcing layers. Optimizations are performed for different configurations of local reinforcements to determine the most effective way of placing the reinforcing layers. Significant improvements in the strength are obtained with minimal added mass through optimization. The findings of this study have significant implications for enhancing the design of notched composite structures.