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

Abstract

3D integrated woven spacer composites with thickened face sheets are fabricated successfully. Static compression and impact behavior are analyzed to evaluate the effect of thickened face sheets. The results show that thickened face sheet is an important influence parameter, warp compression and impact properties have been improved significantly than those of composite without thickened face sheets. Moreover, the damage and failure mechanism is significantly different. The main failure mode under flat compression is an abrupt rigid breakage of core fiber bundles. However, the thickened face sheets reduce the shear stress that transfer to core fibers. For warp compression, there is no face sheets fracture or dislocation, the local shear fracture occurs on the thickened face sheets. In regard to low-velocity impact, the strength of thickened face sheets dominates the failure, the damage is mainly manifested as the penetration of the top and bottom face sheets, matrix cracking, interface debonding, micro-buckling, as well as tearing and breakage of core fibers.

Sandwich Structures with Prismatic and Foam Cores: A Review

“…And the accuracy of the analytical model was verified by experiments and finite element analysis . The low‐velocity impact response of 3D‐integrated‐core sandwich laminates filled with and without foam, with and without additional GFRP or CFRP face sheets was investigated . Vaidya et al studied the properties of stitched cores with and without foams around the reinforcing core members.…”

“…The weak interface between the face sheets and the core of the traditional sandwich structures is one of their major drawbacks. Several studies have been carried out to strengthen the interface bonding including integrated design of face sheets and core, stitching techniques and increasing of the bonding areas . Several technologies have been introduced for sandwich structures improving their mechanical performance and multifunctionality.…”

A parametric investigation into the flexural properties of singly curved composites reinforced with 3D-integrated woven fabrics

“…In addition to skin, the empty core has a low shear resistivity [5] which causes the structure to perform weakly under compressive, impact, and shear loadings. In order to overcome the mentioned drawbacks and improve mechanical properties of 3DIWF composites, two useful methods were utilized by many researchers, injecting foam into the core and thickening the face sheets [10,[18][19][20][21]. Their results showed that by introducing foam into the core, shear resistivity of the core could be improved.…”

“…Moreover, flexural modulus and shear modulus increase as foam density increases. On the other hand, other studies showed that face sheet thickness is a vital parameter influencing mechanical performance of 3DIWF composites [18,20,21]. For instance, Li et al [20] investigated the effect of thickening face sheets on mechanical properties of 3DIWF composites.…”

“…Their results revealed that by thickening the face sheets, with or without foam in the core, the bending load-bearing capacity could be improved considerably. Furthermore, another study concluded that edgewise compressive and impact properties proposed a significant improvement compared to non-thickened face sheets [21]. Hu et al [22] carried out experimental investigation on the failures of 3DIWF composites.…”