Aircraft arresting systems (AAS) are critical safety components required for the operation of fighter aircraft, particularly during aborted take-off or emergency landing scenarios. The most significant challenge in the development and certification of these systems is the high-cost full-scale dead-load testing required to verify their performance under various aircraft mass and entry-speed conditions. This study presents a novel and fully domestic test system that reproduces the kinetic energy input defined in the MIL-STD-3036 standard by using high-inertia flywheels driven by electric servomotors. The proposed system stores the required energy in dual flywheels and transfers it to the arresting barrier through a controlled release mechanism, thereby replicating real aircraft-entry conditions without the need for jet engines, runways or physical dead-load vehicles. The study focuses on the conceptual design and analytical modelling of the proposed system. Dynamic analyses were conducted to determine flywheel geometry, material selection, allowable stresses, rotational speeds and energy absorption capacity. The system was shown to meet the highest energy level defined in the MIL-STD-3036 test matrix, while being designed to enable accurate and controlled evaluation of arresting force, torque response, angular deceleration and stopping time. Experimental validation has not yet been conducted and is planned as part of future work. The results demonstrate that the proposed test system provides an economical, repeatable and safe alternative to conventional dead-load tests and enables performance evaluation, maintenance verification and certification of AAS. Furthermore, the system offers a scalable platform for future arresting technologies, including those designed for unmanned aircraft and next-generation military platforms.

A theoretical and experimental framework for novel metamaterial with programmable damping properties is presented. This material system is able to switch between elastic-dominated and damping-dominated regimes with different overall stiffness under dynamic loading depending on the external stimulus. The unit cell combines an auxetic and a bellow-like layer separated by an interface through which the amount of media flow can be tuned depending on the lateral strain. A simplified analytical model is derived to analyse the programmable damping effect. The model is further extended with a fluid-dynamics approach to link the effective damping properties with geometrical parameters to aid with the practical design of the metamaterial. Afterward, experiments are conducted on a macroscopic level using laser-sintered unit cells to validate the functionality of the concept both with air and water as media within the unit cells. To conclude the work, initial results on microscopic-level unit cells fabricated by two-photon lithography are introduced to showcase the scalability of the concept. This work provides an experimentally validated theoretical framework for future investigations to design unit cells with programmable damping on different length scales for applications requiring tailored dynamic energy dissipation.

Metal–resin interpenetrating phase composites (IPCs) have been produced by spontaneously infiltrating unsaturated polyester resin into porous stainless steel fibrous preforms under vacuum conditions. The compressive behaviors of the IPCs were investigated and the fractures were examined. The compressive strength and elastic modulus increase with increasing fiber fraction. The structures, compressive behaviors, and energy absorption capacities of the IPCs exhibit anisotropy. A higher compressive strength, lower elastic modulus, and lower energy absorption efficiency are observed in the through-thickness direction. The energy absorption efficiency slightly decreases with increasing fiber fraction in a certain range rather than monotonically increasing or decreasing. The energy absorption efficiency in the in-plane direction is superior to that in the through-thickness direction. Finer fibers improve the strength and elastic modulus but have little influence on the energy absorption efficiency. Resin collapse, fiber necking, and debonding are the main failure types observed in the composites.

Vehicle energy absorbing components usually have a curved shape to avoid interference with other components like engine, driving system and fuel tank, etc. Crush behaviour of the S-shape square tubes, as a simplified model of front member of a vehicle body, is investigated in the present study. Experimental and numerical investigation into the quasi static crushing of such tubes was performed. Experimental tests were carried out with cross head speed of 5mm/min. Finite element analysis was performed using ABAQUS/Explicit to simulate quasi-static tests conditions. The predicted crushing characteristics such as global deformation mode, plastic folding mode and load-displacement response obtained by numerical approach were found to be in good agreement with the experimental results. The validated numerical model was then used in the parametric study to examine the effect of design parameters such as wall thickness, web width, curve angle and radius of curvature on the energy absorption capability of the S-shape square tubes. It is shown that some interesting relationships can be discovered by the parametric study to be used as useful design approach for improving the performance of the S-shape tubes.

Self-trapping, stopping, and absorption of an ultrashort ultraintense linearly polarized laser pulse in a finite plasma slab of near-critical density is investigated by particle-in-cell simulation. As in the underdense plasma, an electron cavity is created by the pressure of the transmitted part of the light pulse and it traps the latter. Since the background plasma is at near-critical density, no wake plasma oscillation is created. The propagating self-trapped light rapidly comes to a stop inside the slab. Subsequent ion Coulomb explosion of the stopped cavity leads to explosive expulsion of its ions and formation of an extended channel having extremely low plasma density. The energetic Coulomb-exploded ions form shock layers of high density and temperature at the channel boundary. In contrast to a propagating pulse in a lower density plasma, here the energy of the trapped light is deposited onto a stationary and highly localized region of the plasma. This highly localized energy-deposition process can be relevant to the fast ignition scheme of inertial fusion.