Application of an Additive Manufactured Hybrid Metal/Composite Shock Absorber Panel to a Military Seat Ejection System

Abstract

In this work, a preliminary numerical assessment on the application of an additive manufactured hybrid metal/composite shock absorber panels to a military seat ejection system, has been carried out. The innovative character of the shock absorber concept investigated is that the absorbing system has a thickness of only 6 mm and is composed of a pyramid-shaped lattice core that, due to its small size, can only be achieved by additive manufacturing. The mechanical behaviour of these shock absorber panels has been examined by measuring their ability to absorb and dissipate the energy generated during the ejection phase into plastic deformations, thus reducing the loads acting on pilots. In this paper the effectiveness of a system composed of five hybrid shock absorbers, with very thin thickness in order to be easily integrated between the seat and the aircraft floor, has been numerically studied by assessing their ability to absorb the energy generated during the primary ejection phase. To accomplish this, a numerical simulation of the explosion has been performed and the energy absorbed by the shock-absorbing mechanism has been assessed. The performed analysis demonstrated that the panels can absorb more than 60% of the energy generated during the explosion event while increasing the total mass of the pilot-seat system by just 0.8%.

Tool Wear and Milling Characteristics for Hybrid Additive Manufacturing Combining Laser Powder Bed Fusion and In Situ High-Speed Milling

“…To improve the surface quality of selective laser molten parts and thus to enable those applications, which require superior surface roughness at least on the technically operating, functional surfaces, tight tolerances [ 1 ], restrictive process standards [ 2 , 3 ], or sterilizability in medical applications [ 4 ], 3D-printed parts are, generally, post-processed in downstream processes by means of, e.g., turning, milling, or short-blasting, respectively [ 5 , 6 , 7 ]. In order to reduce the manufacturing efforts in such process chains, different hybrid approaches have been developed that combine additive with subtractive processes [ 8 , 9 , 10 , 11 ].…”

Heat Source Modeling and Residual Stress Analysis for Metal Directed Energy Deposition Additive Manufacturing

“…AM is in the center focus, due to its limitless design manufacturability, various customized material deposition, and ability to automate the manufacturing process, which are few key factors that capitalize over traditional manufacturing methods. AM has achieved immense growth, due to progress in several fields, such as numerical simulations, materials modeling, software development related to AM, customized powder materials preparation for AM, characterizing techniques, and so on [ 1 , 2 , 3 , 4 , 5 ]. Virtual engineering, with the help of numerical modeling, is a powerful tool for the swift progress of AM technology.…”

On the Effects of Core Microstructure on Energy Absorbing Capabilities of Sandwich Panels Intended for Additive Manufacturing

“…According to this enabling technology, complex geometries can be 3D printed in both polymer and metallic materials [18][19][20][21]. In particular, with L-PBF metal additive technologies, due to the micron precision of the sintering laser, it is possible to achieve ad hoc lattice domain maximising energy performance, while retaining internal voids and limited thickness.…”