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The purpose of this paper is to explore the basic loading state in local loading forming process of large-sized complicated rib-web component, which is important for understanding process characteristic, controlling metal flow and designing preformed geometry of the local loading forming process. Moreover the analytical models for different loading states are established to quickly predict the metal flow.

Through analysis of geometric characteristic of large-sized complicated rib-web component and the deformation characteristic on planes of metal flow by local loading method, a representative cross-section is put forward and designed, which could reflect the local loading forming characteristics of large-sized complicated rib-web component. Finite element method (FEM) is used to analyze the stress and metal flow, and the analytical models of metal flow are established by using slab method (SM).

Three local loading states and one whole loading state are found in the local loading forming process of representative cross-section. Further, four loading states also exist in local loading forming process of large-sized complicated rib-web components. With the metal distribution in the process, some local loading states may turn into whole loading state. For the representative cross-section, the relative error of metal distribution between SM and FEM results is less than 15 per cent, and the relative error of metal in the rib cavity between SM and FEM results is less than 10 per cent.

Metal flow can be controlled by adjusting the loading states in the process. According to the metal flow laws in different loading states, a simple unequal-thickness billet can be designed to achieve initial metal distribution, and then, the secondary metal distribution can be achieved in the process.

The purpose of this research is working out of a new forming technology of flat parts with ribs from magnesium alloys with the application of a three-slide forging press (TSFP) for the aircraft industry.

New possibilities of forming aviation parts with ribs gives the application of a prototype TSFP. This press consists of three moveable tools and has wider technological possibilities than typical forging machines. It was assumed that this machine (press) application would allow for obtaining ribbed flat forgings from magnesium alloys of good functional and resistance qualities. A characteristic feature of such forgings forming is the working movement of two side tools, which upset the billet in the form of a plate; the result of their action is forming of one or more ribs in the plane central part. It is possible to use the upper punch to form appropriate rib outline. Theoretical research works based on simulations by means of finite element method were conducted for three cases of the process: semi-free forging of parts with one rib, semi-free forming of forgings with two ribs and forging in closed impression of parts with one rib of triangular outline. The first experimental tests were made on a TSFP for the variant of semi-free forging of parts with one rib.

Research results show that there exists the possibility of realization of forming process of parts with ribs according to the conception assumed by the authors. Positive results of theoretical analyses justify the purposefulness of conducting experimental verification for the proposed theoretical solutions of the forging processes of parts with one rib of triangular outline and with two ribs.

Production of flat parts with ribs from magnesium alloys basing on the worked out by the authors’ technology will allow for improving functional and mechanical properties of parts and for lowering their manufacturing costs. At present, such aviation parts are imported to Poland in the form of casts, which are expensive and not always fulfill the requirements. Additionally, large amount of machining at manufacturing of this type of parts generate larger price at their production.

Forging technology of parts with ribs in a TSFP is unique on a world scale. The advantages of this technology are the process material savings and better resistance properties of the formed forgings with ribs than parts obtained in a traditional way.

The properties of materials under impact load are introduced in terms of metal, nonmetallic materials and composite materials. And the application of impact load research in biological fields is also mentioned. The current hot research topics and achievements in this field are summarized. In addition, some problems in theoretical modeling and testing of the mechanical properties of materials are discussed.

The situation of materials under impact load is of great significance to show the mechanical performance. The performance of various materials under impact load is different, and there are many research methods. It is affected by some kinds of factors, such as the temperature, the gap and the speed of load.

The research on mechanical properties of materials under impact load has the characteristics as fellow. It is difficult to build the theoretical model, verify by experiment and analyze the data accumulation.

This review provides a reference for further study of material properties.

THE idea of a dual analysis in finite elements of a given structure was put forward in Ref. 4. The first analysis should be of the displacement type, using conforming displacement models of the finite elements. This results in a continuous, piecewise differcntiable displacement field in the whole structure, for which linear elasticity theory predicts lower bounds to the local static influence coefficients. The second analysis should be based on equilibrium models of the finite elements. The stress field within the structure is then continuously transmitted across the interfaces and satisfies detailed equilibrium conditions in the interior of each element. This property furnishes upper bounds to the influence coefficients.

The purpose of this paper is to use numerical methods early in the airframe design process and access the structural performance of wing leading edge devices made of different materials and design details, under bird strike events.

Explicit finite element analysis was used to numerically model bird strike events.

Structural performance charts related to materials and general design details were drawn to explore the design space dictated by the current applicable airworthiness requirements.

This paper makes use of the current capability in the numerical tools available for structural simulations and exposes the existing limitations in the terms of material modelling, material properties and fracture simulation using continuum damage mechanics. Such results will always be in the need of fine-tuning with experimental testing, yet the tools can shed some light very early in the design process in a relative inexpensive manner, especially for design details down selection like materials to use, structural thicknesses and even design arrangements.

Bird strike simulations have been successfully used on aircraft design, mainly at the manufactured articles design validation, testing and certification. This paper presents a hypothetical early design case study of leading edge devices for appropriate material and skin thickness down selection.

This paper gives a review of the finite element techniques (FE) applied in the area of material processing. The latest trends in metal forming, non‐metal forming and powder metallurgy are briefly discussed. The range of applications of finite elements on the subjects is extremely wide and cannot be presented in a single paper; therefore the aim of the paper is to give FE users only an encyclopaedic view of the different possibilities that exist today in the various fields mentioned above. An appendix included at the end of the paper presents a bibliography on finite element applications in material processing for the last five years, and more than 1100 references are listed.

Sandwich construction with aluminium honeycomb cores bonded to faces with the adhesive films Redux 775, 775R and Bloomingdale FM‐47 is discussed. Drawings showing its applications to a series of components for various hypothetical aircraft arc included. Sandwich materials for supersonic aircraft of the types now entering production are reviewed, as well as the application techniques of the new Redux films. Some rules gathered from experience for the design of components with honeycomb cores, and solutions of special design problems with hypothetical wing panels, are treated. The paper then deals fairly fully with results from a programme of FFA investigations on this type of structure. The specimens discussed were bonded with Redux 775 and FM‐47 and consisted partly of tensile tests on cores, compressive tests on sandwich columns and shear tests on various sandwich webs. Design curves have been plotted in some cases. Further results are presented showing the influence of temperature on the shear strength of an aluminium alloy core and Redux 775 and FM‐47 films. Also a few creep results are given where the object of the tests has been to determine the optimum curing temperature and time for applying Redux 775 to yield minimum creep values. The room‐temperature results illustrate the excellent properties of honeycomb structures and the elevated‐temperature results indicate that bonded uninsulated aluminium sandwiches can be retained, even when the temperature due to kinetic heating approaches 70 deg. C. Finally, some remarks regarding future developments are made on various new ‘temperature‐resistant’ adhesives and on combinations of various materials for sandwich panels with external insulation, suitable for certain types of the next breed of supersonic aircraft.

THE efficient design and construction of the latest types of Swedish military aircraft, with wings with high critical Mach numbers, has necessitated a thorough investigation into the structural behaviour of swept and delta wings of both the thin and thick types. It is the main purpose of this paper to present some important test results and pertinent details of some of the small scale models which have been built to supplement the theoretical estimation of the stress distribution and deflexion patterns. In some cases these models have also been constructed to provide information on certain unusual structural configurations, which would have otherwise taken many months to obtain by using approximate theoretical methods. The stress distributions for each model are illustrated in such a way that comparison between the different types of structures may readily be made.

THIS article is concerned with the type of multi‐cell box found in wings, fins and tail planes, etc. It does not include the effect of axial constraint applied to the box root inducing differential bending of the box spars, or the type of box whose individual cells have vastly different rates of change of cross sectional properties, i.e. a twin cell box with one cell remaining constant in area and the other tapering sharply—this type would require special analysis, in which the loads imposed on the internal ribs, due to their finite stiffness, would need investigating.

This paper's aim is to focus on the design, manufacture and test of a stiffened panel in composite material with integrated longitudinal foam‐filled stiffeners, spar and rib caps, using one‐shot liquid infusion (LI) process, reducing weight and number of subparts respect to metallic reference baseline P180 Avanti vertical fin.

Extensive activities in computational applications in order to improve the efficiency of the design process finite element analysis/structural sizing codes have led to an optimised engineering design process that resulted in a successful stiffened carbon fibre reinforced polymer panel design in terms of weight and number of parts with respect to the metallic baseline.

The composite panel has fulfilled all the design requirements (reduction of mass and number of parts with respect to the metallic reference baseline) overcoming the certification static test, and confirming the reliability of the theoretical analyses.

The composite aircraft components, conceived as unitized structure by one‐shot process, guarantee not only a mass reduction, compared to aluminium components, but assure also the reduction of the number of subparts and of the assembly process cycle time. On the other hand, the LI technology implies the development of more specific and advanced techniques to control the manufacturing and the weight.

The stiffened panel is the most used component in the aircraft structures; the solution shown in this work can find applications in many parts of an aircraft.

The results obtained in this work can be useful to those who work in aeronautical structural departments with the aim to reduce weight and subparts of the airframe.