A novel methodology to measure the transverse Poisson’s ratio in the elastic and plastic regions for composite materials

Abstract

A new methodology to measure the transverse Poisson’s ratios in fibre-reinforced composite materials was developed. Transverse tensile and transverse compressive standardised tests were instrumented using digital image correlation equipment to measure the lateral strain field of the specimens. A thermoplastic-based composite material was used to describe the proposed methodology. The elastic transverse Poisson’s ratio exhibits a different behaviour in tension than in compression, its value being greater in compression than in tension. Assuming no plastic strain in the longitudinal direction, the plastic transverse Poisson’s ratio in compression suggests no volumetric plastic strains for small axial plastic strains, however, plastic dilatancy was observed when the amount of compressive plastic axial strain increases.