© 2025 The Author(s)Assessing the bending response of infiltrated reinforcement fabrics is crucial in wet compression molding (WCM) as it affects macroscopic wrinkling. Binder-stabilized fabrics may be used in WCM to improve handleability and reduce defects, necessitating their characterization. This study examines the bending behavior of an infiltrated binder-stabilized carbon fiber unidirectional non-crimp fabric (UD-NCF), focusing on the effects of viscosity, loading rate, and binder pre-activation. Infiltration reduces bending stiffness compared to dry fabric owing to lubrication and lower tow-stitch friction, while higher loading rates increase bending stiffness for all considered conditions. Moreover, binder pre-activation increases fabric stiffness by enhancing tow-stitch cohesion and friction. As the first investigation on infiltrated binder-stabilized UD-NCF bending, this work advances understanding of the complex bending response.

© 2025 Elsevier Ltd.The dynamics of hanging chains, a topic studied since the 18th century, has relevance in contemporary engineering applications, particularly in low-frequency vibration control. This paper concerns the use of hanging chains to mitigate vibrations of a host structure. To enable predictions to be made and to identify the key parameters of the chain, four models are developed, each of which contributes to the predictions and physical insight in a different way. The first is a continuous model, which is only strictly valid at relatively low frequencies, when the length of a chain link is small compared to the wavelength at the top of the chain. The second is a finite element model considering a chain made of discrete rigid links, which is valid up to much higher frequencies. The other two models are an approximate hybrid lumped parameter/continuous model, which provides some additional physical insight, and a very simple approximate lumped parameter model, which can be used to predict the vibration attenuation effectiveness of a chain when connected to a host structure. Laboratory measurements are presented to assess the validity of the models and to demonstrate the efficacy of chains as a passive vibration control device.

© 2025 Elsevier Masson SASThe increasing demand for ultrafast aerospace transportation and high-performance strategic systems has fueled the interest in air-breathing hypersonic vehicles. However, their design still presents considerable challenges owing to the tight coupling between the thermodynamic and flight dynamic phenomena. This study proposes an integrated simulation framework capable of representing the coupled behavior of a six-degree-of-freedom hypersonic vehicle and a multi-stage scramjet engine model. The proposed framework incorporates atmospheric variation, aerodynamic and mass models, actuator dynamics, and energy-based thrust modeling under transient conditions. The objective was to evaluate the dynamic and thermodynamic responses of a vehicle during flight maneuvers. To that end, several scenarios were simulated, including descent and transition to level flight, acceleration and deceleration. The results demonstrate that the model captures the strong transients associated with ignition, control response, and inlet compression modulation. Thermodynamic analysis revealed consistent heat transfer, irreversibility, and exergy trends, with the combustion stages being the main source of entropy generation. The propulsive efficiency and specific impulse evolve coherently with thrust demand and flight conditions, whereas control logic successfully stabilizes critical thermodynamic parameters during maneuvering. These findings validate the capacity of the framework to reproduce the coupled dynamics of scramjet-powered hypersonic flights, providing a solid basis for future studies on optimization and thermodynamic analysis.

© 2025 Acta Materialia Inc.High solidification rates and in situ heat treatments are commonly found in additive manufacturing (AM) of steels, resulting in a complex and far-from-equilibrium microstructure. Therefore, standard post-processing heat treatments commonly applied to wrought steels can favor the occurrence of different phenomena and can change the phase transformation sequence, due to the unique microstructure obtained by powder bed fusion – laser beam (PBF-LB). This work reports the microstructural evolution of 15-5 precipitation hardening (PH) stainless steel manufactured by PBF-LB during direct aging heat treatments at 621 °C (AMS H1150 standard condition), a route used to increase fracture toughness due to the martensite reversion and precipitates coarsening. The reversion of martensite into a Ni-rich austenite, predicted by kinetic calculations, was confirmed by high-energy X-ray diffraction (HE-XRD), being preferentially nucleated close to the copper-rich precipitates (CRPs), which can act as a preferential nucleation site. CRPs presented an oval shape, as confirmed by electronic microscopy (SEM and TEM) and atom probe tomography (APT). Fast Fourier transform (FFT) analysis of high-resolution TEM (HR-TEM) images suggests CRPs still present the metastable untwined 3R-type structure after 8 h, rather than the most stable FCC structure. The presence of retained austenite, inherent to PBF-LB-processed PH steels, affects the CRPs evolution in different phases, and the CRPs themselves act as nucleation sites for Nb(C,N) secondary precipitation. These findings emphasize the necessity of microstructure-oriented heat treatment routes to unlock the full potential of additively manufactured PH stainless steels.

© 2025 Elsevier LtdThis study explores the thermal behavior and volatilization kinetics of JET A-1 aviation kerosene and Farnesane, a sustainable aviation fuel compound, and their blend through thermogravimetric analysis in an oxidative atmosphere. For such, experiments were conducted under a synthetic air atmosphere at three different heating rates (10, 15, and 20 ℃ min−1), and results showed that Farnesane exhibits high thermal stability up to approximately 80 °C, followed by rapid decomposition, whereas JET A-1 starts decomposing at 35 °C and volatilizes gradually until reaching 109 °C. The minimum energy required for the volatilization process of Farnesane to start taking place is about four times greater than that for JET A-1, i.e. 53.72 KJ mol−1 and 12.67 KJ mol−1, respectively. Activation energy of 8.88 KJ mol−1 was found for the Farnesane-JET A-1 blend, which is a lower than that for pure kerosene, thus revealing a beneficial and synergistic effect between them, which should ease the initial stages of fuel vaporization, since it is of paramount relevance for efficient combustion.

© 2025 Elsevier B.V.The increase in the production of Sustainable Aviation Fuels (SAFs) is essential to promote the decarbonisation of the aviation sector by 2050. In this study, Raman spectroscopy was used as a tool to investigate structural changes in samples of JET A-1, Farnesane, and a 10 % Farnesane blend with JET A-1(designated FarnJET10), exposed to an oxidative atmosphere for 3, 24, and 48 h. The results show that JET A-1 exhibits higher oxidative stability, while Farnesane is prone to degradation, with a rapid decrease in vibrational band intensity across all regions of the spectrum. The FarnJET10 blend exhibited intermediate oxidative behaviour, but the findings indicate that the presence of Farnesane compromises the stability of JET A-1. Principal Component Analysis (PCA) was applied to distinguish the stability and chemical behaviour of the fuel samples. The first two principal components explained 98.91 % of the total spectral variation, with PC1 and PC2 accounting for 85.44 % and 13.47 %, respectively. The PCA scores demonstrated a clear separation between the pure fuels and the blend, highlighting the distinct oxidative responses and structural changes induced by exposure to an oxidising atmosphere. These findings highlight the oxidative vulnerability of the SAF/fossil fuel blend and its effects on fuel stability, which may compromise performance during storage and operational use in aviation systems.