Real service requirements of the assembly performance and joining properties of design components are critical for composite usage in the aerospace industry. This experimental study offers a novel and comprehensive analysis of dry drilling optimization for glass-reinforced, high-performance epoxy matrix composites used in aerospace structures, focusing on thrust force and delamination. The study presents a first-time investigation into the combined effects of spindle speed (1000, 2250, 4000 and 5750 rpm), feed rate (0.2, 0.4, 0.6 and 0.8 mm/rev) and tool diameter (3 and 5 mm) using a custom-designed drill tool specifically developed for this application, filling a gap in the current literature. By employing the Taguchi design of experiments, the study identified that medium spindle speeds (2250–4000 rpm), lower feed rates (0.2 mm/rev) and smaller tool diameters (3 mm) provided optimal conditions for minimizing thrust force and delamination. These results present actionable insights into improving the structural integrity and performance of drilled aerospace-grade composite components, offering innovative advancements in both the aerospace and defense industries.

Purpose: This study aims to demonstrate the numerical application of differential quadrature (DQ) methods and show the experimental application of free vibration analysis of fiber-metal laminated composite (FML) plates with various boundary conditions.Design/methodology/approach: The FMLs are hybrid structures consisting of fiber-reinforced polymer matrix composites such as carbon, glass, aramid and different metal sheets, and are currently widely used in the automobile, aircraft and aerospace industries. Thus, free vibration analysis of these hybrid materials is necessary for the design process. The governing equations of motion are derived based on the classical plate theory. The DQ, generalized DQ (GDQ) and harmonic DQ (HDQ) differential quadrature methods have been used to solve the governing equations of an FML composite plate numerically. The accuracy and convergence of the numerical model have been verified by comparing the results available in the published literature with the results obtained from these methods. Moreover, an experimental procedure has been performed in order to compare the results against those of the numerical methods.Findings: It is noteworthy that a high degree of similarity and accuracy was observed between the numerical results obtained by the DQ methods and the experimental results. Thus, the present study validates the applicability of the DQ methods for designing the FML composite plates.Originality/value: In this study, the advantages of the DQ methods have been demonstrated differently from previous studies on the vibration analysis of the FML plates.

Additive manufacturing, commonly referred to as 3D printing, stands out for its ability to rapidly produce complex objects, contrasting with conventional manufacturing techniques such as machining, forging, welding, and powder sintering. Today, additive manufacturing is often used to create functional and lightweight final products. Therefore, free vibration analysis is crucial in the design process of structures composed of such materials. The objective of this study is to investigate the effects of variations in parameters such as opening angle, curvature radius, and thickness of 3D-printed curved beams made of PET-G, PLA, and ABS materials, which have clamped-clamped boundary conditions, on the in-plane vibration characteristics of the structure. The vibration parameters of the curved beam structure, modeled using the ANSYS finite element program, have been determined. Numerical results have been compared with findings from the literature to validate the accuracy and applicability of the proposed model. Consequently, it has been found that changes in the material and geometric properties of 3D-printed curved beams significantly influence the natural frequencies of the structure.