STRUCTURE POWER AIRCRAFT FUSELAGE 5774 TRAINER

The analysis process using software aims to determine whether an object or material is suitable for use or not before carrying out the manufacturing process. To find out whether the material is strong or not when applied to the aircraft, an analysis is carried out using the ABAQUS CAE 6.14 software. This software will show the stress value that occurs in the sandwich composite structure when it receives the load experienced by the aircraft.

Mechanical behavior of sandwich structure composites for helicopters

The visible part of the floors of a commercial aircraft has long been a standard issue for virtually every commercial aircraft, mainly due to the weight of the materials from which they were made. Floor parts must provide mechanical strength and dimensional stability, while keeping the weight of the aircraft as low as possible for maximum efficiency. The design of the 787 Dreamliner and the Airbus A380 aircraft brought new opportunities in the use of the sandwich composite structure, mainly due to their light weight and high strength-to-weight ratio. Thus, this paper investigates the mechanical behavior of sandwich composite panels composed of two sides of carbon fiber laminate and Nomex honeycomb core obtained in the autoclave and developed under the RoRCraft CompAct grant. The technical approaches of this work are mainly focused on the compression behavior and especially on the compression after impact behavior of the hybrid sandwich composite structure, for defining and obtaining an optimal structure for the floors. These mechanical tests are decisive for such materials and have been performed in accordance with international ASTM standards.

Towards the Prediction of Sandwich Composites Durability in Severe Condition of Temperature: A New Numerical Model Describing the Influence of Material Water Content during a Fire Scenario

An advanced fire thermal model was developed to predict the evolution of the temperature and decomposition gradient across a sandwich composite structure when exposed to high temperatures (fire). This model allows the prediction of a large numbers of parameters, such as thermal expansion, gas mass storage, porosity, permeability, density, and internal pressure. The highlight of this model is that we consider, in the sandwich constituents (core and skins), additional parameters, such as changing volume porosities, other coupled constituents (as infused resin in the balsa core), and what make the main originality of the present approach: moisture content (free and bounded water). The time dependence of many parameters, i.e., among others, the combustion advancing front and mechanical properties, can be predicted in a large number of material and fire scenarios. The proposed approach was validated in the case of sandwich panels, with glass/polyester or glass/vinyl ester skins and balsa core, exposed to high temperatures up to 750 °C. The influence of water on the thermal and mechanical responses is also highlighted.

Fabrication and Mechanical Properties of POSS Coated CNTs Reinforced Expancel foam core Sandwich Structures

Background:: Sandwich structures are progressively being used in various engineering applications due to the superior bending-stiffness-to-weight ratio of these structures. We adapted a novel technique to incorporate carbon nanotubes (CNTs) and polyhedral oligomeric silsesquioxanes (POSS) into a sandwich composite structure utilizing a sonochemical and high temperature vacuum assisted resin transfer molding technique. Objective:: The objective of this work was to create a sandwich composite structure comprised of a nanophased foam core and reinforced nanophased face sheets, and to examine the thermal and mechanical properties of the structure. To prepare sandwich structure, POSS nanoparticles were sonochemically attached to CNTs and dispersed in a high temperature resin system to make the face sheet materials and also coated on expandable thermoplastic microspheres for the fabrication of foam core materials. Method:: The nanophased foam core was fabricated with POSS infused thermoplastic microspheres (Expancel) using a Tetrahedron MTP-14 programmable compression molder. The reinforced nanophased face sheet were fabricated by infusing POSS coated CNT in epoxy resin and then curing into a compression stainless steel mold. Result:: Thermal analysis of POSS-infused thermoplastic microspheres foam (TMF) showed an increase in thermal stability in both nitrogen and oxygen atmospheres, 19% increase in thermal residue were observed for 4 wt% GI-POSS TMF compared to neat TMF. Quasi-static compression results indicated significant increases (73%) in compressive modulus, and an increase (5%) in compressive strength for the 1 wt% EC-POSS/CNTs resin system. The nanophased sandwich structure constructed from the above resin system and the foam core system displayed an increase (9%) in modulus over the neat sandwich structure. Conclusion:: The incorporation of POSS-nanofillier in the foam core and POSS-coated nanotubes in the face sheet significantly improved the thermal and mechanical properties of sandwich structure. Furthermore, the sandwich structure that was constructed from nanophased resin system showed an increase in modulus, with buckling in the foam core but no visible cracking.