Carbon fiber-reinforced polymer (CFRP) laminates are extensively utilized in aerospace and advanced engineering fields because of their outstanding strength-to-weight ratio and superior fatigue durability. However, despite their high in-plane strength and stiffness, CFRP laminates are inherently susceptible to delamination. This weakness stems from the relatively low interlaminar strength of the resin-rich interfaces between layers compared to the much stronger in-plane fiber reinforcement. During mechanical processes such as drilling and punching, out-of-plane stresses and interlaminar shear forces develop, concentrating at these weak interfaces. This study investigates the delamination behavior of CFRP laminates with 3 to 7 plies under drilling and punching, focusing on the effects of ply count and drilling speed. Experimental tests were conducted using an 8 mm punch and drill bit at 2500, 3000, and 3500 rpm, reflecting typical workshop practices for M8 fastener holes. Scanning electron microscopy (SEM) analyses at different magnifications were used to quantify delamination extent. A three-dimensional finite element model was created in ABAQUS/Explicit, integrating the Hashin failure criterion to predict damage initiation within the plies and cohesive surfaces to simulate interlaminar delamination. The analyses show that with proper support, punching can approach the damage levels of drilling for thin CFRP plates, but drilling remains preferable for thicker laminates due to better integrity and tool longevity.

The use of additive manufacturing (AM) has a lot of potential for manufacturing geometrically challenging parts, components, and even assemblies. To ensure the effective adoption of additive manufacturing by the aviation industry and to expedite the standardization process, a certification roadmap is essential. This study offers a thorough analysis of the issues facing the qualification and certification of additively made parts, components, and assemblies that could be used on commercial passenger air vehicles. It also provides information regarding the general standards of AM process. After outlining the principles of technical application for the AM process, the current status of the regulations, and rules created by national/international airworthiness authorities and communities are then summarized and analyzed in terms of the manufacturing of aviation-grade parts, components, and assemblies.

This paper experimentally determinates the calculation of an Unmanned Aerial Vehicle (UAV) and analyzes the design criteria within four different scenarios. The UAV to be designed is a loiter munition UAV system. A mobile or equipment such as a parachute and/or airbag. The UAV may be operable day and night conditions, capable of 2-3 hours of flight hours, and will be launched from a catapult. The UAV navigation system is compact and easily controlled by a personal Global Positioning System (GPS). The mentioned UAV will have a vast operational capability, especially for defense and border security activities since it is equipped with advanced avionics and a small physical footprint for covert operations. As a consequence of this research, it can be claimed that the UAV's mid-wing, twin-tail, and relatively light body will have three axis stability and offer numerous benefits, particularly in terms of operational cost.

In today’s aviation industry, research and studies are carried out to manufacture and design lightweight, high-performance materials. One of the materials developed in line with this goal is glass laminate aluminum-reinforced epoxy (GLARE), which consists of thin aluminum sheets and S2-glass/epoxy layers. Because of its high impact resistance and excellent fatigue and damage tolerance properties, GLARE is used in different aircraft parts, such as the wing, fuselage, empennage skins, and cargo floors. In this study, a survey was carried out and a low-velocity impact model for GLARE materials was developed using the ABAQUS (2014) version V6.14 software and compared with the results of low-velocity impact tests performed according to the American Society for Testing and Materials (ASTM) D7136 standard. This article introduces a novel integrated approach that combines detailed numerical modeling with experimental validation of GLARE 4A FMLs under low-velocity impact. Leveraging ABAQUS, a robust FEM featuring explicit analysis, cohesive resin interfaces, and custom VUMAT subroutines was developed to accurately simulate energy absorption, dent depth, and delamination. The precise model’s predictions align well with test results performed according to ASTM D7136 standards, exhibiting less than a 0.1% deviation in the displacement (dent depth)–time response, along with deviations of 4.3% in impact energy–time and 5.2% in velocity–time trends at 5.5 ms.

Havacılık kazalarının oluşumu çoğunlukla birden fazla nedenden kaynaklanmaktadır. Diğer bir ifade ile havacılık kazaları birçok etkinin birleşiminin bir sonucu olarak meydana gelmektedir. Bu etkilere, üretim süreçleri, bakım faaliyetleri, beşeri unsurlar, meteorolojik şartlar, sertifikasyon kontrolleri ve pist durumu gibi hususlar örnek olarak verilebilir. Diğer taraftan aynı uçak tipindeki ardışık kazalar, doğal olarak dikkat çekicidir. 29 Ekim 2018’de Endonezya’da ve 10 Mart 2019’da Etiyopya’da meydana gelen B-737 Max ticari yolcu uçağı kazaları bu ardışık kazalara örnektir. Bu çalışmada söz konusu kazalar pilotaj ve mühendislik perspektifinden, sertifikasyon süreçleri açısından ele alınmaktadır.