Experimental study on the charpy impact failure of 3D integrated woven spacer composite at room and liquid nitrogen temperature

Abstract

The charpy impact experiments on the 3D integrated woven spacer composites with six types of core heights are performed at room and liquid nitrogen temperatures (as low as -196 o C). Macro-fracture morphology and SEM micrographs are examined to understand the deformation and failure mechanism. The results show that the impact energy increase with the increase of the core height at both room and liquid nitrogen temperatures. Meanwhile, the impact properties at liquid nitrogen temperature have been improved significantly than that at room temperature. Moreover, at room temperature, the penetration fracture of the face sheets, the tearing and pulling out of the core fibers as well as the cracking of the matrix is the main damage and failure patterns. However, at liquid nitrogen temperature, the matrix crushing dominates the failure. Less fibers fracture and brittle fracture feature becomes more obvious. In addition, with the increase of the core heights, the damage of composites has been reduced significantly at room and liquid nitrogen temperatures.

Micromechanical modelling of the compression strength of three-dimensional integrated woven sandwich composites

“…Three-dimensional IWSCs consist of two woven fabric faces and an integrated hollow core. These two parallel faces are bonded together using pile yarns which keep a deEned distance between the top and bottom skins to form an integrated hollow core and woven into the deck layers, thus forming integrated woven sandwich (or spacer) composites [8][9][10]. The use of IWSC panels in manufacturing of sandwich composites has presented a new concept on this topic.…”

Static and dynamic mechanical behavior of 3D integrated woven spacer composites with thickened face sheets

“…Their studies also showed that the face sheets carried the main dyanmic loading and determined its failure mode. Li et al [16] studied the charpy impact properties and failure mechanism of 3D integrated woven spacer composites with six types of core heights at room and liquid nitrogen temperatures. However, the face sheet of conventional 3D integrated hollow core sandwich composite is very thin and weak in sustaining loading, which greatly restricts its engineering applications.…”

A Novel Hybrid Silk Fibroin/Polyurethane Arteriovenous Graft for Hemodialysis: Proof‐of‐Concept Animal Study in an Ovine Model

“…However, a tendency of the IH thickening to slow down between day 60 and day 90 was noted on the venous side (V1–V4, Figure 6L), and the regime IH thickness in all the subjects was slight to minimal (<500 µm), and considerably lower as compared to values found with ePTFE grafts in similar animal models (>800 µm). [ 12,23 ] In our opinion, this represents the confirmation that Silkothane grafts succeed in limiting the acute short‐term body response which commonly leads other synthetic prostheses to failure. Indeed, longer‐term investigations (e.g., 6–12 months) are needed to get deeper insight into the chronic progression of intimal thickening with our grafts: ideally, remodeling into a native‐like vessel, the Silkothane graft shall grant performances comparable to the ones of arteriovenous fistulae, where intimal thickening is accepted as intrinsic into the process of vein arterialization, and generally chronicizes on non‐impairing regime levels.…”

“…The presence of endothelial cells, predominantly aligned along the direction of blood flow, is considered of utmost importance to enhance graft compatibility when aiming at vessel repair, [ 12,14 ] and it usually occurs on ePTFE grafts only if they are coated with specific treatments (e.g., cell‐binding peptides). [ 23 ]…”