The transverse compression of PPTA fibers - Part II - Fiber transverse structure

The single fiber transverse compression test (SFTCT) is applied to KEVLAR a nd TWARON poly (para-phenyleneterephthalamide) fibers, both continuous fila ment and staple, and of varying denier and heat-treatment, as well as M5 ri gid-rod fibers. Resulting force-deflection curves are analyzed by a Hertzia n contact model, to give the effective transverse modulus, and estimate the stress state in the fiber at the onset of yield. Confocal microscopy and f inite element simulation are used in conjunction with SFTCT to describe the inelastic, transverse deformation of PPTA. The effects of skin-core struct ure and anisotropy in the fiber cross-section are discussed. (C) 2000 Kluwe r Academic Publishers.