Failure Analysis of Triaxially Braided Composite Under Tension, Compression and Shear Loading

In the current study, continuum damage mechanics-based progressive failure analysis was performed to predict the initiation and progression of failure in triaxially braided textile composite unit cell under tensile, compressive and shear loading conditions. Geometric and finite element modeling was done at mesoscale unit cell level, with repeating nature of the unit cell considered through the application of periodic boundary condition. Analysis result was first validated with experimentally obtained stress-strain curve for uniaxial tension loading. Then, failure prediction was extended for tension, compression and shear failure loading in different directions. Depending on the out-of-plane boundary condition, single ply and infinitely stacked symmetric and antisymmetric plies were also considered to investigate the effect of stacking sequence on the in-plane properties. Detailed examination of failure modes at different damage initiation and propagation stages was presented. After full mechanical properties were obtained from mesoscale virtual testing, macroscale failure analysis of laterally loaded triaxially braided composite cylinder was performed using predicted properties. The result was then compared with test result for validation of the method used.