Abstract This study investigates the use of Corrosion Health Monitoring (CHM) systems to detect and manage corrosion in aviation environments, with a specific focus on enclosed areas within aircraft structures. Corrosion poses significant risks to airport facilities and aircraft, and CHM systems offer real-time monitoring and data-driven approaches for proactive corrosion management. Through case studies conducted at two different test sites, the effectiveness of deploying advanced sensors was demonstrated in identifying corrosion-prone areas, optimizing maintenance schedules, and enhancing safety and structural integrity. The study highlights the variability in corrosion rates between openair and enclosed conditions, emphasizing the need for tailored prevention strategies. It also discusses the challenges of integrating CHM systems into existing maintenance practices and airport infrastructure, addressing issues such as sensor placement, data management, and regulatory compliance, and outlines future directions for R&D in this critical area. By incorporating CHM systems, the aviation industry can transition from reactive to predictive maintenance, improving the reliability and lifespan of assets while reducing costs.

Abstract Non-destructive testing (NDT) plays an important role in aircraft maintenance and repair processes, ensuring the structural integrity necessary for safe operation. The paper presents the design and evaluation of an animated, low-cost robotic NDT system tailored for inspecting composite bonding agents. The system integrates commercially available components, including a three-degree-of-freedom robotic arm and a Raspberry Pi 4B, managed by custom Python software with a user-friendly graphical interface. Mechanical Impedance Analysis (MIA) and Eddy Current Testing (ET) methods were employed to assess the system’s performance on representative test specimens. Results indicate that the system delivers reliable and accurate measurements comparable to commercial tools like the MAUS V, while offering simplicity and modularity. Limitations such as scanning speed and handling of complex geometries are acknowledged, with potential solutions proposed for future enhancement. The system provides an affordable and customizable alternative for NDT automation in the aerospace industry.

Abstract Military aircraft are subjected to highly variable and unpredictable loads due to diverse mission profiles, armament configurations, and individual piloting styles. This variability complicates the definition of precise load spectra, particularly in cases where data loss occurs due to Flight Data Recorder (FDR) malfunctions or data mishandling. This paper investigates the use of different flight parameters, such as load factor (nz ), barometric height (Hb ), and horizontal velocity (Vp ), to define load sequences for the PZL-130 “Orlik” TC-II military trainer aircraft. These sequences were then used to evaluate crack propagation using Compact Tension (CT) specimens. The results show that the incorporation of additional flight parameters improves the accuracy of crack propagation predictions when compared to direct strain measurements. This study highlights the potential of using available flight data to develop reliable load spectra for fatigue life estimation in military aircraft, even when direct load measurements are not financially feasible.

Abstract This study addresses the challenge faced by Finite Element Analysts when choosing between free and mapped meshes, especially in terms of convergence stability and solution accuracy. The investigation focuses on 3D solid models under static structural loading, analyzed using Ansys® and MSC Patran®. Both free and mapped mesh types, employing equivalent 3D solid elements, are used to assess an aircraft structural component under design load conditions, with fixed boundaries. For free meshes, Tet10 elements in Patran (equivalent to Solid 72 in Ansys) are used, whereas for mapped meshes, CPENTA / CHEXA elements in Patran (equivalent to Wed6 / Hex8 in Ansys) are employed. Mesh convergence studies ensure that discretization does not affect the numerical solution. Notably, a significant stress increase is observed with successive refinement of free meshes, while mapped meshes achieve mesh independence at coarser refinement levels. Comparison of fringe plots indicates the same location for maximum deformation and equivalent stress in both free and mapped mesh models. The findings demonstrate that free meshes tend to underpredict maximum deformation and equivalent stress compared to mapped meshes, with both meshes showing deformation and stress at consistent locations. The findings underscore the importance of carefully choosing the appropriate mesh type, particularly when analyzing critical structural components, to ensure reliability and accuracy in FEA simulations.

Abstract The landing gear is a critical safety component of any aircraft, playing a key role in managing the significant loads experienced during landing and ground maneuvers. In the case of the I-31P aircraft, a redesign of the I-23 landing gear system, required comprehensive testing to validate its performance, after change of landing gear parts manufacturer and minor updates to materials and technologies. This study focuses on the dynamic testing of the I-31P nose landing gear (NLG), particularly to assess its energy dissipation and fatigue resistance under operational conditions. Dynamic tests, performed in accordance with CS-23 standards, utilized strain gauges to monitor potential stress concentrations, especially on the half-fork design. Results demonstrated that the I-31P nose landing gear meets the required safety standards, with key performance metrics such as deflection and load factors within acceptable limits. The findings also highlighted the importance of continued monitoring for potential fatigue issues, offering valuable insights for future design enhancements.

Abstract The work presented is the result of the implementation of diffraction measurements: phase composition and stresses resulting from additive manufacturing process of nickel superalloy Inconel 718 components print. With the help of diffraction methodologies, the key parameters from the point of view of the quality of prints and their strength were determined. The existence of individual phases in the material after printing was demonstrated, and the surface variation of the stress values was presented, showing its dependence on the geometry of the printed part – measurements were made at various points on the surface of samples with different geometries. In addition, the variation of the stress level was shown depending on the distance of the measurement point from the build platform on which the additive manufacturing process was carried out. Components were printed on the surface of a single build plate in order to study the effect of printing differently oriented samples with respect to the platform geometry, as well as the mutual effect of the temperature of samples printed first on the stress state of elements printed in subsequent steps of the procedure, and the effect of the temperature of elements printed later on the rate of temperature decrease, and consequently on the stress state, of elements printed first.

Abstract This study focuses on the application and improvement of diffraction measurement methodologies for the optimization of manufacturing parameters of CoCr alloy components made by additive manufacturing (AM) – particularly for Mediloy S-Co alloy specimens made using Laser Powder Bed Fusion (LPBF) additive manufacturing. We measured the phase composition of specimens obtained in AM processes, the measurement of residual stresses resulting from the manufacture of these printed parts, as well as the effectiveness of stress relaxation through the use of heat treatments dedicated to this type of material. Findings reveal several insights into how printing strategies affect the porosity and residual stresses in additive manufacturing. Specimens with higher porosity, particularly those created using specific strategies that resulted in lower energy densities, exhibited lower residual stresses. Notably, printing direction and energy density were found to significantly affect the mechanical stresses within the specimens, with directional choices playing a critical role in the final properties of the parts. Additionally, our findings underscore the complex relationship between various printing parameters and the development of mechanical stresses, highlighting the impact of adjustments in printing strategy on the properties of printed components.

Abstract In response to the steady rise in global demand for energy resources such as gas and oil, there is a pressing need to enhance the efficiency and safety of pipeline transportation systems. These systems, integral for transferring vast amounts of energy, must operate under increasingly higher pressures and larger diameters without compromising reliability. This study focuses on utilizing finite element analysis (FEA) to investigate the influence of crack orientation and the presence of defects on the fatigue life of pipelines. By simulating internal pressure scenarios and examining various defect characteristics with the AFGROW software, this research applies damage tolerance principles to offer insights into the fatigue behavior of pipelines. The findings can be applied to extend the operational life and ensure the integrity of these critical infrastructures, thereby supporting the sustainable and safe transport of energy resources.

Abstract The present article discusses the three-dimensional (3D) printing process in the fused deposition modeling (FDM) or the fused filament fabrication (FFF) technique using the author’s own philosophy of shaping the printing head path. The main requirements are the possibility of eliminating supports and reducing or even eliminating the need for the mechanical processing of 3D prints before their final assembly. The presented methodology was implemented in a computer program written by the author and was used to print typical parts used in aviation. Individual methods of shaping parts typical for the construction of small flying models, such as wings and fuselages, and methods of strengthening and connecting them have been discussed. The proposed solutions are illustrated with photos of readymade prints. This article also discusses the issues that printing high-quality parts may encounter and how to avoid them. Some attention has also been paid to the materials used for printing and their suitability in the construction of aircraft and their fatigue strength.

Abstract The currently accepted rules that are applied to the aircraft cable-control systems’ operational use are based on the reactive maintenance idea and the comparative tests, inspections, and diagnostics performed at the mandatory intervals. Fatigue tests of the aviation cables are commonly conducted by bending in the range of ± 90° with constant load. Aircraft cable-control systems are subject to a number of random loads and deformations. Additionally, forces and their values are modified by the wear and tear of cable-pulley raceways, elastic deformations, and changes caused by temperature. The actual values of tension of aviation cable-control systems are relatively low, and bending usually does not exceed the maximum of ± 35°. Moreover, the forces characteristic of the control cables are nonlinear functions of the control surface deflection. This means that the typical fatigue tests we employ help with only comparative estimations and acceptance tests. It is not possible to estimate the operational durability of the systems and forecast inspections and diagnoses intervals based on the mentioned results. The present article utilizes the operational profiles of selected aircraft categories to determine the stochastic load-related deflection spectra for the preparation of cable fatigue-testing programs. Operation profiles are built considering a group of aircraft belonging to the same category, performing similar missions, for example, training missions, photogrammetric missions, aircraft towing, e.q., and having a similar share in the total resource. The special stands for the selected cable fatigue tests have been proposed. The cable test stand ensures the real stochastic loads for the cable use and other actual conditions of load. The proposed stand enables the simultaneous testing of more than one cable at different deformation parameters, for example, wrap angles. The results of the proposed method and tests can be used to estimate the operational durability of aviation-control systems as well as for inspection and diagnosis intervals as well.