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This study aims to evaluate the development of composites made of epoxy (E) resin with different weight percentages of polypropylene (PP) and graphene oxide (Go) to form nanocomposite plates.

A hand lay-up process was used to develop 21 different composites, with varying concentrations of PP (5%–35%) and Go (5%–35%). A ternary composite of E matrix was produced by combining binary fillers PP and Go (5%–35%) in a 1:1 ratio to a (95%–5%) solution. With the help of adopting the melt condensation deal to extract Go, the modified Hummers method was used to make Go platelets.

Through field emission scanning electron microscopy (FESEM) and X-ray diffraction investigations, the particulate’s size and structural characteristics were identified. Based on the FESEM analysis of the collapsed zones of the composites, a warp-and-weft-like structure is evident, which endorses the growth yield strength, flexural modulus and impact strength of the composites.

The developed nanocomposites have exceptional mechanical capabilities compared to plain E resin, with E resin exhibiting better tensile strength, modulus and flexural strength when combined with 10% PP and 10% Go. When compared to neat E resin, materials formed from composites have exceptional mechanical properties. When mixed with 10% PP and 10% Go, E resin in particular displays improved tensile strength (23 MPa), tensile modulus (4.15 GPa), flexural strength (75.6 MPa) and other attributes. Engineering implications include automobile side door panels, spacecraft applications, brake pads and flexible battery guards.

The purpose of this paper is to describe the work of IDMEC, a not‐for‐profit R&D private association located in Porto and Lisbon, Portugal.

The paper focuses on IDMEC's R&D activities, focusing on aeronautics.

Together IDMEC‐Porto and INEGI provide answers to R&D challenges in the broad area of aerostructures, from fracture and fatigue problems to advanced composites for space applications.

The paper offers a concise presentation of the IDMEC's R&D activities in the field of aeronautics.

The effects of space environment on friction and wear and on the selection of lubricants and self‐lubricating materials for spacecraft mechanisms are discussed, with special emphasis on the ultrahigh vacuum of space. Experimental studies have demonstrated the feasibility of using selected oils and greases to lubricate lightly loaded ball bearings without replenishment for periods of over one year under the following conditions of operation : speeds of 8,000 rpm, temperatures of 160 to 200°F., and vacuum of 10–8 torr. Over one‐half year of successful operation has been achieved under similar operating conditions with self‐lubricating retainers of reinforced Teflon, provided that the loads were light. Bonded films of molybdenum disulfide have given shorter lifetimes and poor repro‐ducibility. Metal‐to‐metal slip‐ring contacts introduce excessive electrical noise into circuits when operated in vacuum of 10–7 torr. The noise (as well as the friction and wear) can be markedly reduced by providing a small amount of oil vapor, sufficient to maintain a pressure on the order of 10–6 torr, or by incorporating molybdenum disulfide into the brush material.

Due to their outstanding thermal stability, polyimides are now being carefully considered for use as matrix resins, adhesives, films and coatings. If successful, this unique class of polymers could greatly extend the present upper limit of 177°–205°C achievable in aerospace work with even higher temperatures and longer service life.

Dr D. C. EVANS looks at some of the options open in selecting a plain‐bearing arrangement designed to operate where an external lubricant supply cannot be incorporated for reasons of environment or expediency.

More than 20 years’ experience in development and application of techniques and instrumentation for evaluation of space environment effect on polymer materials and adhesively bonded joints in active experiments on‐ and overboard low Earth orbit space stations Salyute, Mir and the international space station (ISS) is reviewed. Six techniques and instrumentation sets were developed and tested for remote control of polymer materials and adhesive joints structure/properties changes during long‐term exposure in space environment. This made it possible to evaluate visco‐elastic and dielectric properties, surface defectiveness and crack resistance as material parameters, which are sensitive to structure changes of polymer materials and adhesive joints and are their important service characteristics. Some experimental results of the techniques and instrumentation, ground and space tests are presented.

Accles & Pollock Ltd. of Oldbury, Worcestershire, a TI Steel Tube Division company, will be exhibiting a comprehensive range of precision steel tube and tubular products, including plain, annularly convoluted and thin wall tube, at Farnborough.

The purpose of this study is to focus on the developments of carbon fiber reinforced polymer (CFRP) panels with stepwise graded properties on adhesive layer. The various arranges of the graded properties of the adhesive layer have been checked according to experimental results of the literatures and based on applicability.

The finite element (FE) models and experimental modal tests of the manufactured CFRP sandwich panel specimens have been investigated. The core thickness, core density and orientation of the fiber direction of the sandwich panel face – sheets have been parametrically checked based on modal behavior. Two fully free and fully clamped boundary conditions (BC) have been checked in stepwise graded adhesive zone (SGAZ) cases and first five non-zero natural frequencies (NF) have been compared. Dynamic response of the SGAZ includes modal analysis and transient dynamic loading have been performed numerically with ABAQUS 6.12 well-known FE code.

The first non-zero NF of SGAZ Case 4 was 11.69 per cent higher than homogenous Case 2 and 7.06 per cent lower than Case 1 in fully free boundary conditions. A total of 26.38 per cent is the greatest discrepancy between fist five non-zero NFs of all cases with two BCs (Case 1 vs Case 2 in fully clamped BC). Maximum structural damping behavior and minimum stress picks have been studied during transient dynamic loading analysis of CFRP panel with SGAZ. SGAZ Case 3 (middle adhesive with lower modulus) has increased the maximum structural damping while reducing the minimum out of plain tip displacements during transient dynamic loading by 111.26 per cent in comparison with homogenous Case 2. Also, Case 3 has reduced the Mises stress picks on the adhesive region by 605.68 per cent.

Making a stepwise graded adhesive region (without any added mass) has been shown that it is a novel and useful way to achieve a wide range of stiffness on CFRP panels.

Development of the sandwich panels with various stiffness and damping properties.