Numerical investigation on central tearing behaviors and propagation mechanisms of coated warp-knitted fabrics

Abstract

To reveal the central tearing behaviors and propagation mechanisms of the architectural non-crimp fabric (NCF) composites with an initial crack, a microscopic finite element (FE) model was proposed and developed to simulate the tearing propagation process of materials in this paper. Firstly, the experimental program including the central crack tearing test of NCF composites and uniaxial tensile test of yarns was performed for gaining the material parameters. Secondly, a finite element (FE) model was developed and validated from the good agreement between numerical and experimental results. Furthermore, tearing damage mechanisms and failure performances of the NCF composites with an initial central crack were simulated and analyzed. Finally, the effects of initial crack length, yarn orientation, and arch curvature of weft yarn on mechanical properties were investigated in depth. The analysis and comparison results indicate that the NCF composite shows the unneglectable orthotropic characteristics, in which the initial crack length, yarn orientation, and arch curvature of weft yarn have the significant effects on the mechanical properties. This paper thus provides an adequately feasible and accurate FE model for the numerical simulation on the central tearing propagation behaviors of the NCF composites with an initial crack.

Influence of water soaking on the ultimate tensile strength of polyester-based coated woven fabrics

“…Performed investigations of the coated woven fabrics have shown that the mechanical parameters are highly influenced by temperature changes [13][14][15]; changes in behaviour under uniaxial, biaxial and creep loadings [16][17][18][19][20][21]; glass threads based and PTFE-coated woven fabrics occur a reduction in the tensile strength resulting under waterlogged [22,23]; prove degradation of the tensile strength exposed to weathering and ageing impacts and cyclic loading [24][25][26][27]; exhibits highly material nonlinearity with identified viscoelastic, viscoplastic behaviour [28][29][30][31][32][33][34]; puncture resistance strength increases with the increase of weight percentage of fibres and initial notch significantly reduce the ultimate strength [35][36][37][38]; the failure strength depends on the stress ratio and off-axial angle [39][40][41][42]. The investigations are also performed on: tearing behaviours and tearing strength propagation mechanisms [41,[43][44][45][46], off-axis tearing properties [47,48], achieving 3D strain surfaces on coated woven fabrics, and refined biaxial test procedures [49,50], modelling multi-scale progressive damage to investigate the damage and failure behaviours…”