Lateral Strain
Transverse dimensional reduction occurs perpendicular to an applied longitudinal tensile force in flexible textile structures or individual filaments. Under tension, poisson contraction forces fabric width narrowing or fiber diameter compression as internal structural components realign along the loading axis. The phenomenon describes elastic or plastic deformation under uniaxial tension, ceasing when external tensile loading is removed or material failure occurs.
Transverse Deformation
Tensile forces applied along warp yarns pull interlacing weft threads tight, forcing open crimp structures to flatten while reducing overall fabric width. In elastic woven goods, poisson contraction decreases cross-sectional area during extension, altering fabric porosity and air permeability under load. Optical strain analysis systems track width reduction across central gauge lengths to calculate Poisson ratio values for technical textiles.
Fiber packing density inside yarn bundles increases during axial extension, raising inter-fiber friction. High-density weave structures resist lateral strain better than open knit loops.
Structural Narrowing
Excessive lateral narrowing distorts garment fit under strain. Uncontrolled width reduction causes seam pulling and pattern misalignment during wear.
Mechanical Response
Technical fabric designers select weave geometries and yarn orientations that manage lateral deformation under tension. Quantifying poisson contraction ensures consistent performance in narrow elastics and architectural textile membranes.
