Failure analysis of plain woven glass/epoxy laminates: Comparison of off-axis and biaxial tension loadings

Abstract

An experimental study was focused on investigation of the failure properties of plain woven glass/epoxy composites under offaxis and biaxial tension loading conditions. Four fibre orientations (0 ,15 ,30 and 45 with respect to the load direction) were considered for off-axis tests and two biaxial load ratios for biaxial tests to study failure characteristics and mechanism. Four classical polynomial failure criteria-Tsai-Hill, Hoffman, Tsai-Wu and Yeh-Stratton-were analysed comparatively to predict offaxis and biaxial failure strength of the composites. For failure prediction of the plain woven composites under multiaxial tension loads, the Tsai-Wu criterion was modified by introducing an interaction coefficient F 12 obtained from 45 off-axis or biaxial tension tests and the Yeh-Stratton criterion was modified with the interaction coefficient B 12 ¼ 0 or obtained from the biaxial tension test. The former criterion was found to have higher accuracy. Finally, according to macroscopic and microscopic studies, the failed specimens showed mostly distinct failure with a specific fracture orientation, mainly exhibiting fibre or fabric tensile fracture mode and a combination of matrix cracking and delamination, both in off-axis and cruciform samples.

The effect of off-axis angles on the mesoscale deformation response and failure behavior of an orthotropic textile carbon-epoxy composite

“…It suggested that this phenomenon may be a result of the interaction of the tensile and shear stresses. A similar mechanical response was also found by Cai et al [13,21] and Koohbor et al [4,15]. Godara et al [17] employed the digital image correlation technique (DIC) method to experimentally investigate the effects of the fiber orientation on the mesoscale deformation and the multiple failure mechanisms of the woven textile composite.…”

“…Failure is expected to occur in the brushy fracture region, which supports the description earlier. Compared with the fractured sections of the fibers of on-axis specimens, there are numerous sites of oblique fracture sections of the fibers for off-axis specimens [13] (Fig. 10 d), in some extent indicating the characteristics of off-axis failure mechanism at micro-scale.…”

“…The composite laminates were post-cured in the mold at 130 °C for two hours and taken out from the mold after cooling to 60 °C. The symmetrical weaving architecture enables the mechanical properties to be the same in the warp and weft directions [13]. Therefore, in this work, only four off-axis angles (i.e.…”

“…However, such textile laminates are often subjected to local off-axis tensile loading due to its wide application in plane and shell structures. [13]. Therefore, it is essential to experimentally assess deformation response and failure behavior in such loading cases, which will contribute to the safety and reliable design of composite structures.…”

Anisotropic Mechanical Response and Strain Localization of a Metallic Glassy-Fiber-Reinforced Polyethylene Terephthalate Fabric

“…Existing studies provide different perspectives for understanding the influence of the fabric architecture and loading direction on the mechanical properties, and the damage behaviors of woven fabric composites [ 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. Cai et al [ 6 , 7 ] investigated the tensile properties of unidirectional and woven fabric glass/epoxy composites under on- and off-axis loading and found that the Tsai-Wu failure criterion is more accurate with a modified interaction coefficient under multiaxial stress conditions compared with the Tsai-Hill, Hoffman and Yeh-Stratton criteria. Zhou et al [ 8 ] studied the damage evolutions of woven fabric composites with three different fabric architectures by monotonic and cyclic on- and off-axis tension tests.…”