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DIRECT observation (see Fig. 1) on a strip of veneer cut at an angle other than 0 deg. or 90 deg. to the grain shows that a bending moment parallel to the long axis of the strip is accompanied by a twist, in addition to the usual bending, and further, that the resistance to bending is higher when the accompanying torsion is prevented than when it is permitted. Similar phenomena are observed when the strip is subjected to a pure twist about the long axis; the distortion is again a combination of flexure and torsion, and a higher resistance to torsion is obtained when the accompanying bending is suppressed than when it is permitted.

Presents a novel method of measuring nine fabric properties considered to be important in tailorability and garment performance. Presents results of tests performed on a limited number of fabrics.

The purpose of this study is to investigate the effect of the considerable Ag₂SO₄ content on the electrical and dielectric properties of (AgPO₃)_1−x(Ag₂SO₄)_x ion glass system as well as to extract thermodynamic parameters.

Glass samples of (AgPO₃)_1-x(Ag₂SO₄)_x with different mole ratios of Ag₂SO₄ [x = 0.00, 0.10,0.15,0.20 and 0.25] have been synthesized and used. X-ray diffraction and differential thermal analysis were used to investigate structural and thermal properties, and then the electrical characterizations of the bulk glasses were performed in different frequency and temperature range.

For different ratios of Ag₂SO₄ on AgPO₃, the bulk conductivity is enhanced with increasing the amount of Ag₂SO₄ until the composition of x = 0.20, after which the conductivity decreases. The general behavior of both ε’ and ε” decreases with increasing frequency and increases with increasing temperature. Complex impedance analysis studied by Z‘−Z’ and Cole–Cole plot at different temperatures revealed that bulk resistance decreases with temperature.

The calculated values of activation free energy, enthalpy and entropy change for different compositions of (AgPO₃)_1-x(Ag₂SO₄)_x showed an increase in activation energy and enthalpy when Ag₂SO₄ ratio is increased in (AgPO₃)_1-x(Ag₂SO₄)_x composition up to 20%, and then there is a decrease in their values at x = 25%, which may be explained based on non-bridging oxygen.

As CAD fabric modelling becomes more widespread there is a need to study the applicability of fabric property parameters which are used in predicting fabric behaviour. The anisotropical mechanical behaviour of woven fabrics, fusible interlinings and their composites were studied on order to invesigate the accuracy of equations used to predict the anisotropic linear elastic behaviour of fabric for in plane and bending deformation. Bending, shear and tensile properties were measured using KES©F equipment. Results showed that the orthotropic model of anisotropy can be applied for the qualitative modelling of woven and fusible interlining fabrics and that simple mechanical models for bending properties can be used for their composites.

Aims to analyse the stress distribution in a circular flexible sheet. Part II verifies the theory with experimental work.

The investigation includes analysing the stress distribution in a circular flexible sheet clamped around its circumference under an externally applied force by a spherical object. Movement of the material normal to its original plane is then related to the external force and the elastic properties of the sheet, i.e. the elastic modulus and the Poisson's ratio. The effects of the size of the force‐applying object, relative to the sample radius, are also investigated.

The relationship between the applied force on the centre of a flexible sheet material by a spherical object and the sag of the sheet was derived. Poisson's ratio has an important role on the mechanism of deformation, restricting the extension of the sheet when it is high and intensifying the discontinuity of the strain at the interface.

The work could be expanded to industrial fabrics and to composite materials.

The two papers provide a first step in an attempt for a better understanding of the stresses involved in bagging of a linear elastic sheet. They provide the basis for the development of fabrics that can withstand bagging problems. This research may also put forward improved methods of measuring bagginess. Some of the theoretical work may be used to predict bagginess of fabrics based on properties.

The paper has two improvements on previous work: the inclusion of the effect of fabric Poisson ratio, and the suggestion of a better method of calculating the overall anisotropic properties.

THE increase in speeds of modern aircraft types has brought with it many stiffness criteria for the prevention of flutter, entailing an accurate estimate of the stiffness and rigidity of structural parts, and if the skinning of such plywood stressed skin units as fuselages, wings, and control surfaces is to be of reasonable weight, and the relevant Air Ministry requirements are to be simultaneously satisfied, it becomes essential that more rigid methods of stiffness estimations of plywood panels should be employed than has been done hitherto. The difficulties in getting theory and practice to agree are many and may be enumerated as follows: