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IN discussing possibilities of new uses for wood and plastics in aircraft construction, emphasis is often laid on production problems and economic questions—shortage of aluminium, for instance. But the problem of weight is so important that it is quite impossible to consider new ways of aeroplane designing without touching it.

The use of computers on the shop floor has been slight compared with their widespread acceptance at higher levels in the manufacturing environment. Today, there is an urgency to redress this imbalance by investing in modern production facilities, but progress is being restricted by the void between the operational requirements of the upper and lower levels. The Discrete Cell Controller (DCC) is considered to be capable of satisfying this role. This article considers the measures taken by a consortium of industrial and academic partners to determine the specification of a DCC and, in particular, identify the generic content.

The purpose of this paper is to present a numerical model of coupled heat, moisture transfer and their effects on the mechanical deformations of wood during the drying process.

Coupling among heat, moisture, and mechanical deformations is solved consecutively by use of sparse solver of MATLAB. The weighted residual of the equilibrium equations of drying process of wood, based on finite element method, is investigated. The stress and plastic strain increments can be solved with Newton's method.

The numerical model is applied to a plain strain problem of a long wood board taken from the outer region of the wood log. Numerical simulation reveals the stress reversal during the drying process. The mechanical deformations and the principle stresses of a three‐dimensional wood board in consideration of the orthotropic properties are presented.

Plane strain and plane stress are analysed. The tangential modulus is derived. The transformation of the stress and strain tensors between the local coordinate system resulting from the cylindrical properties of wood and the global one is evaluated. Selection of element type for temperature, moisture content and displacement is discussed.

NO technical development in all our industrial history has been as highly glamorized as the subject of plastics. It has shown an amazing degree of popular appeal for several reasons, including probably the idea of synthesis from “coal, air and water”, the beauty of colour and finish in decorative effects, and the fact that the objects of early manufacture were those of common use by the general public. Feature writers have regrctably enjoyed a general field‐day revelling in the subject, and unfortunately there has been a tendency towards certain misconceptions and exaggerations in such writings. Plastic aeroplanes now flying, plastic automobiles and plastic homes of the future have been described. Actually there is no such thing today as the plastic aeroplane. The plywood airframe has attained great importance owing to the advent of plastic glues, and what might be termed a “plywood plastic” aircraft is still actually a high‐grade plywood. The plastic automobile bodies envisaged today are secondary structures to be built over a metal framework. The post‐war homes will undoubtedly have dozens of items in which plastics will play a part, but primary load‐carrying structures are not among these components as yet. The plastic industry itself has recently become somewhat concerned about the dangers attendant on over‐glamorization and some remedial action has been studied.

WOOD, in the natural state, possesses certain great advantages, and some grave disadvantages, as a structural material. The same is true of the untreated metals. But, whereas nowadays the metallic raw products are, in general, transformed into materials of higher quality by careful smelting, alloying, and other processes, wood is still employed to a great extent in its raw state, i.e., as it occurs in Nature. All previous attempts to improve wood have yielded quite inadequate results, judged by the standard of the advances made in this direction in the field of metallurgy.

CELLULOSE is Nature's strong material. It is the chief constituent of cotton flax and wood. Wood can be turned into sugars by treatment with hydrochloric acid Bergius process) and by certain termites; horses and cows break down the cellulose in grass into sugar before digesting it. So it is not surprising that the cellulose polymer is built up of what are practically molecules of a glucose (“Barley Sugar”). Each β glucose unit is twisted about its axis through 180 deg.; the combination of two such units makes up that is called a cellulose unit which has the structure shown in Fig. 2. The cellulose polymer is a long, straight chain made up from these cellobiose units, and each chain probably contains about 70 such units.

IN treating of the glueing of wood one must distinguish between the mere carpentering operation of glueing, in order to produce a strong and watertight joint with the greatest economy of material and weight, and glueing undertaken to improve and enhance the qualities of the wood. For the latter one employs the most modern technical equipment and methods.

ALTHOUGH the modern tendency in aeroplane construction is to produce an all‐metal machine, the time has not yet come when we can definitely say that this or that machine is entirely of metal, there being still a fair proportion of the structure of most light aeroplanes in which wood plays a very important part, both from the point of view of the greater facilities existing for repair and the lesser cost of production.