METHOD OF MEASURING DEFORMATION PROPERTIES OF KNITTED FABRIC WITH BIAXIAL STRESS-STRAIN STATE Russian patent published in 2012 - IPC G01N33/36 

FIELD: physics.

SUBSTANCE: rectangular sample with given length and width dimensions is subjected to uniaxial deformation on a standard tensile testing machine having a loading module, and the relationship between the load and the deformation value is determined (in form of deformation curves), wherein a tubular sample is used for testing. Two plates, whose width is larger than that of the sample, are placed inside the sample and the sample is subjected to a given value of lateral deformation on its width. The sample is tied together with the edge of one of the plates to the grips of the top clamp, and to the lower grips - with the edge of one of the plates and the sample is deformed in the longitudinal direction with uniaxial stretching with relative displacement of the plates of the loading module, while keeping the value of lateral deformation constant during testing, and the relationship between the load and the value of longitudinal deformation for the given value of lateral deformation is determined.

EFFECT: method enables estimation of biaxial stress-strain state and selection of the value of biaxial deformation, which provides a given level of stress state of the material and a level of compression pressure on the support surface.

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