The peculiarities of textile behaviour in biaxial punch deformation

Abstract

The goal of this research work was experimental investigation and evaluation of biaxial punch deformation processes of anisotropic textile materials. The investigation was aimed to solving the following problems: tofind a new criterion for textile behaviour evaluation in punch loading; to evaluate theeffect of material anisotropy for the geometry offormed shell; to determine the straindistribution in anisotropic shell. The experimental data of X‐ray diffraction analysis showed that friction at specimen/punch contact, which earlier was ignored, has a significant effect upon the parameters of the punching process.

The effect of three-layer weft knitted material structure and composition upon performance properties

“…It is known that in the case of isotropic materials, external loading distributes equally in two main directions, whereas in the case of anisotropic materials the main part of external loading falls upon the stronger and less deformable direction, leaving the perpendicular one less loaded and more stretchable. 16,19–21…”

“…This confirmed earlier obtained findings that, in isotropic materials, external loading distributes equally in two main directions. 17,19–21…”

“…These results again confirm earlier findings that during biaxial punching of anisotropic materials, the main part of external loading falls on the less deformable direction, leaving the perpendicular direction less loaded and more stretchable. 17,19–21

Figure 11.Linear dependencies between maximal uniaxial elongation in the wale direction ɛ maxw (a) and the course direction ɛ maxc (b) and maximal biaxial punching height H max .

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“…Nowadays, various investigation methods, such as multi-cyclic bagging, biaxial punching of different garment zones (knees, elbows), multidirectional tension, and relaxation processes are used with the aim of simulating the deformation behavior of sheet materials under exploitation loadings. [16][17][18][19][20][21] The results of earlier investigations show that the biaxial punching test is more reliable compared to uniaxial tension. [16][17][18][19][20][21] Meanwhile, little research has been done to study the effect of yarn content and knitted structure type upon three-layer weft knitted spacer material mechanical behavior, that is, on uniaxial tension, biaxial punching, and fatigue punching characteristics.…”

The Effect of Bonded Seams upon Spatial Behaviour of Knitted Materials Systems

“…Punching was performed with a special device created at Kaunas University of Technology, which was attached to standard tensile testing machine Tinius Olsen H10K [18,19]. Specimen radius was R = 28.2 mm and punch radius was r = 9.5 mm ( Figure 2).…”