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An account is given of the experimental determination of the transverse elastic moduli and yield behavior of some commercially available organic and graphite high-modulus filaments. The experimental technique involves transverse compression of single cylindrical filaments between two parallel flat platens and concurrent measurement of the platen- relative displacements and contact forces on the filaments. A theoretical discussion of the transverse compressional behavior of a linear elastic, homogeneous, orthotropic cylinder is presented. Using the theoretical results and the trans verse load-displacement measurements, a technique is developed for calculating the elastic moduli and maximum shear stresses at yield or fracture. [ABSTRACT FROM PUBLISHER]

A theoretical expression is derived for the variation of the crease-recovery angle of a plain-weave monofilament fabric with orientation of the crease to the thread directions; it involves the constructional parameters of the fabric, the flexural and torsional rigidities of the monofiiaments, and their elastic recoveries from flexural and torsional strains. This expression has been checked for two nylon fabrics, and, with one adjustable parameter, good agreement is obtained between the theoretical and observed polar variations. The variation of the fiexural rigidity of these fabrics with orientation is shown to be in agreement with the theoretical predictions of Cooper. [ABSTRACT FROM AUTHOR]

One of the main factors that determine the crease recovery of a fabric is the bending-recovery behaviour of the constituent filaments. An experimental method is described that enables the bending elastic recovery of filaments to be found for a wide range of initial strains. Possible sources of error in the method are discussed and results are presented for 15-den. nylon monofilament. [ABSTRACT FROM AUTHOR]

An apparatus is described that enables the torsional stress-strain curve and the torsional elastic recovery to be found for filaments; this information is required for a study of the crease-recovery behaviour of fabrics. Results are given for 15-den. nylon monofilament. [ABSTRACT FROM AUTHOR]

An account is given of an experimental investigation of the effects of warp and weft tension, reed-spacing, pick-spacing, and weave type on the width of woven tapes. The observed trends are discussed in terms of the fabric structure and the changes that take place in the unit cells of the fabrics under various weaving conditions. [ABSTRACT FROM AUTHOR]

The retained angle at a crease is considered to be made up of two components: inelastic and frictional. A theoretical scheme has been developed that enables the inelastic component to be calculated from the appropriate fibre, yarn and fabric data and the calculations are illustrated for three fabrics. An experimental investigation of the crease-recovery behaviour of these fabrics, in conjunction with the calculations described above, has established a method of deducing the frictional component from the low-curvature bending-recovery behaviour of a fabric, and it is thus possible to make an estimate of the fabric crease-recovery angle. The calculation has been carried out for a range of fabrics woven from eighteen fibre types, each in four different cover factors, and the results are shown to agree reasonably well with the measured crease-recovery angles for the same fabrics. The experimental results are discussed and some interesting relationships are pointed out; in particular it is shown that fabrics must be well relaxed if the full potential of a high-recovery fibre is to be realized. [ABSTRACT FROM AUTHOR]

A theoretical investigation of the tensile, flexural and torsional behaviour of crimped filaments has been made; the relationships describing the filament behaviour are presented in graphical and in analytical form, and are verified experimentally. Two results are of particular importance in routine textile testing: it is shown that the Young's modulus of staple fibres measured with a tensile-testing machine is not subject to significant error caused by crimp; and a new expression is proposed which enables the optimum tension for the routine yarn-crimp test to be calculated. [ABSTRACT FROM AUTHOR]

Measurements of the bending elastic recovery of native and chemically modified cotton fibres are described; the results are used to estimate the degree of cross-linking in the treated fibres, and to predict the crease-recovery behaviour of fabrics made from the fibres. [ABSTRACT FROM AUTHOR]

The strength of seams produced with a range of sewing threads in four lightweight coated nylon fabrics was investigated. It was shown that a plain weave fabric can be seamed more efficiently than a basket weave fabric of the same weight and strength, and that closely woven fabrics can be seamed more efficiently than more open fabrics of the same weave type. Loss of seaming efficiency was shown to be related to fabric pull-out at the seams, and it was demosntrated that if the pull-out is prevented by appro priate reinforcement it is possible to produce highly efficient seams even in very open fabrics. [ABSTRACT FROM PUBLISHER]

A theoretical analysis of the shear deformation of a fabric under biaxial load was carried out and the amount of twisting deformation of spherical inflated structures made from skewed fabric was calculated and compared with the twisting observed in a model structure. A device was constructed for the measurement of the shear resistance of fabrics, and determinations of this property were made on a range of fabrics in the off-loom, heat-set, and coated states. The theo retical expressions and the experimental results are used to show that twisting deformations could be important in full- scale structures. [ABSTRACT FROM PUBLISHER]

Measurements of the breaking load of woven nylon and Dacron tapes at low and high strain rates showed that the tape strength is reduced at high pick densities and at a particular low pick density; the former was shown to be related to the high level of frictional restraints in the closely woven fabrics, while the latter is associated with the unique geometrical con figuration of the yarn filaments in the particular structure.The effect of various finishing treatments on the strength and the efficiency of translation of yarn strength to fabric strength was studied. The strength of the tapes is greater at high strain rates than at low strain rates for both materials. It was shown that the tapes are very efficient structures (>90%) under all test conditions. For medium pick densities. the efficiency approaches 100% and, under these circumstances, the effect of finishing treatments is minimized. In general, however, the loomstate tapes are strongest, with scouring causing a slight loss in strength, which is almost com pletely restored on treatment with silicone finish.Particular care is needed to carry out tensile tests on tapes at high strain rates, and a method was evolved for testing deliberately weakened specimens in order to avoid jaw breaks. In addition, a new variable radius-of-curvature capstan jaw was developed, which permits the attachment of tapes to other members such that the full potential strength of the tape is realized. It is suggested that a practical routine fastening system could be developed on the basis of the jaw design. [ABSTRACT FROM PUBLISHER]