Evaluation on mechanical properties of ramie fabric under three-dimensional load

For complex stress issues of fabric under practical working environment,mechanical properties of ramie textile were investigated under uniaxial and biaxial directions,bursting and three-dimensional load,and the strain fields of different force bearing modes were characterized by using digital speckle correlation.The poisson ratio is 0.311 4,warpwise and weftwise elastic modulus is 6 624 N /m and 2 656 N /m respectively under biaxial load.Breaking strength under uniaxial force is larger than that in warpwise,but smaller than that in weftwise.Coefficient of variations in both warp-and weftwise are larger when compared with unaxial tension.X direction strain-field under biaxial load fluctuations lies between unaxial tensions of weft and warp.Covariance and correlation analysis showed that the difference of bursting strength under three-dimensional load was primarily determined by bursting ways,correlation coefficient between breaking strength of warp and weft is-0.613.Partial correlation analysis showed that there is 13.72% generated by synergy effects of bursting strength.