Direct Measurement of the Transverse Modulus of Carbon Fibres

Abstract Background The transverse compressive properties are integral to fully utilizing the high performing mechanical of carbon fibres (CF). Direct measurements CFs difficult. Objective A system that directly measures modulus ( E T ) by interference speckle patterns measure sub-pixel resolutions is presented. Methods compression data from an isotropic glass fibre was fitted using elastic contact mechanics model. An initial section observed, which not readily model and systematically removed, resulting in 82 GPa, comparable reported longitudinal tensile L 86 GPa. Results response Ag wire cyclic measured, with behaviour consistent a material undergoing typical stress–strain into stable hysteretic loop. Several were compressed inversely proportional relationship between observed. Transverse moduli 8.2 (0.8), 6.5 (0.7), 4.3 (0.3), 2.1 (0.4) obtained for Toray T300 Mitsubishi Pyrofil HS40, TR50S, Dialead K13312, respectively (numbers parenthesis standard deviations). Conclusion Hysteresis observed some polyacrylonitrile (PAN)-based method ensuring accurate fitting CFs, including load/unload curves, proposed.