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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.

The purpose of this study was to introduce three-dimensional printing (3DP) of functionally graded sandwich foams (FGSFs). This work was continued by predicting the mechanical buckling and free vibration behavior of 3DP FGSFs using experimental and numerical analyses.

Initially, hollow glass microballoon-reinforced high-density polyethylene-based polymer composite foams were developed, and these materials were extruded into their respective filaments. These filaments are used as feedstock materials in fused filament fabrication based 3DP for the development of FGSFs. Scanning electron microscopy analysis was performed on the freeze-dried samples to observe filler sustainability. Furthermore, the density, critical buckling load (P_cr), natural frequency (f_n) and damping factor of FGSFs were evaluated. The critical buckling load (P_cr) of the FGSFs was estimated using the double-tangent method and modified Budiansky criteria.

The density of FGSFs decreased with increasing filler percentage. The mechanical buckling load increased with the filler percentage. The natural frequency corresponding to the first mode of the FGSFs exhibited a decreasing trend with an increasing load in the pre-buckling regime and an increase in post-buckled zone, whereas the damping factor exhibited the opposite trend.

The current research work is valuable for the area of 3D printing by developing the functionally graded foam based sandwich beams. Furthermore, it intended to present the buckling behavior of 3D printed FGSFs, variation of frequency and damping factor corresponding to first three modes with increase in load.

THE application of science and technology to industrial processes over the last twenty‐five years has unquestionably made life for most people more materially satisfying. The paradox is that, side by side with high earnings, there is an almost unprecedented mass of unemployment. This situation puzzles politicians no less than industrialists and union leaders.

FEW workers display greater concentration than the man creating delightful glass objects on a seaside pier during the summer months. He is so intent on his work that he has small interest in the fascinated onlookers. Here is living proof that to the average worker nothing is more important than the nature and content of his job.

The aim of this work is the study the tribological behaviour and tribocorrosion resistance of newly developed multilayer PVD coatings Cr/CrN and CrN/ZrCN applied on nitrided F1272 steel for gear applications.

Tribological characterization has been completed by several tribological tests performed under ball‐on‐disc configuration, extreme pressure tests to determine the maximum load before the films failure and rolling‐sliding tests under line‐contact conditions (35‐40 per cent of sliding). The response of the different coatings to sodium chloride aggressive environment has been simulated by accelerated tribocorrosion tests, combining simultaneously chemical and mechanical factors. The synergistic effect of wear on corrosion behaviour and vice versa, has been studied in order to compare the protective properties of the different PVD coatings developed.

Cr/CrN PVD coating improves wear in almost a 90 per cent compared to the nitrided substrate, presenting a similar behaviour to this one under extreme pressure conditions. CrN/ZrCN coating also improved substrate wear and especially good behaviour for this coating was observed under extreme pressure conditions. Cr/CrN coating strongly decreases micropitting and scuffing effect when it is tested under rolling‐sliding configuration. Under micro‐pitting conditions, coating protects the substrate and reduces the fatigue of uncoated discs. When adhesive wear (scuffing) is studied also Cr/CrN improves notable the nitrided steel performance. Under simultaneously corrosion‐wear conditions, Cr/CrN coating registered the lowest material loss because in this case only corrosion effect contributed to the coated surface degradation being the mechanical contribution inappreciable.

New multilayer coatings with improved wear performance and tribocorrosion resistance have been developed and comprehensively characterized. These coatings can be used in advanced gears for corrosive environmental conditions as well as with biodegradable lubricants.

COMING OUT firmly against a Government scheme for splitting jobs in their sectors is the Council of Civil Service Unions. They say that “The net effect of job‐splitting would be to create a number of part‐time posts from existing full‐time ones which will be seen as an unacceptable dilution of full‐time posts.”

The purpose of this paper is to develop a volatile organic component‐free water‐based binder with improved coating properties from urethane‐alkyd acrylate by emulsion polymerisation.

Alkyd resin based on interesterification of sardine fish and linseed oil (50:50 w/w) was synthesised and reacted with isophorone diisocyanate to form urethane alkyd. The resultant urethane alkyd and acrylic monomers in different ratios were polymerised by emulsion polymerisation to form air‐drying water‐based binders and studied for physicochemical and other coating properties.

Urethane alkyd, co‐polymerised with acrylates by emulsion polymerisation process, can be used to prepare water‐based air‐drying binders with excellent coating and application performance. The increase in acrylate component in the system resulted in improvement of performance properties.

In the present study, refined fish oil (FO) was obtained from sardine fish. Different FOs can be used to produce alkyd resin. Urethane alkyd and acrylic monomers in different ratios can be polymerised by emulsion polymerisation techniques.

The emulsion polymerisation is the most effective technique used to produce water‐based binders with excellent coating properties.

Water‐based binders can be widely used in exterior coatings and waterproofing of cement and roofs.

INDUSTRIALLY the two ‘in’ words today seem to be participation and consensus, the first leading to the second. How these can become a reality in modern business was discussed recently by the London Region of the Institute of Work Study Practitioners.

MODERN man can reach any part of this planet within thirty‐six hours. The people who inhabit it speak around two thousand languages. That is a measure of the difficulty in making human contacts. It makes the Tower of Babel seem like a kindergarten. In view of this, instead of bemoaning that the world has progressed so little, we should marvel that it has progressed so much.

AT THE INTERNATIONAL CONFERENCE ON GEARING arranged by the Institution of Mechanical Engineers in London from the 23rd to 25th September, a special session was set aside for the Discussion of Lubrication and the following papers were presented :—