A physically-based model for the notched strength of woven quasi-isotropic CFRP laminates

Strength prediction in CFRP woven laminate bolted single-lap joints under quasi-static loading using XFEM

“…Hence there is a hole size effect associated with the larger volume of highly stressed material for the larger hole size, even though the nominal stress concentration factor is independent of the hole diameter at a given W/d. This agrees with Belmonte et al's [16] (and with numerous other researchers) findings for the open-hole geometry and this effect was also noted in the corresponding DLJ tests [14]. The effect of clamp-up is more apparent in thin laminates than thicker laminates.…”

“…Similar trends are also observed by Belmonte et al [16] for openhole strength and are attributable to the higher fibre volume fraction of plain weave, even though plain weave exhibits a higher degree of crimp as compared to equivalent five-harness satin fabric. The higher fibre volume fraction in plain weave fabric is attributed to the ability of the fabric to nest the fibres more tightly.…”

“…5 and Table 3. Interestingly, with regard to the magnitude of the bearing stresses at failure achieved, they are greater than the base-line tensile strengths of the laminates, reported in Belmonte et al [16]. True bearing failure was seen more readily in the quasi-isotropic lay-ups compared to the cross-ply lay-ups for the range of joint geometries investigated here.…”

“…These represent a sub-set of those tested by Belmonte et al [16] in their investigation of open-hole behaviour. Details of the lay-ups and some of their key mechanical properties are shown in Table 1.…”

Strength Prediction of Notched Woven Composite Plates Using a Cohesive Zone Approach

“…In that sense the damage resembles stable self-similar crack growth, suggesting that a fracture mechanics-based model is a physically reasonable one to use. A similar study was carried by Belmonte et al (2004) on woven quasiisotropic and cross-ply CFRP. Although the opaque nature of the CFRP means that direct observations of damage are less straightforward, there was evidence of tow failure before specimen failure.…”