Experimental and numerical study of the behavior of epoxy foam‐filled 3D woven spacer composites under bending load

Abstract

In this work, three‐dimensional woven spacer glass fiber/epoxy composites (3DWSC) and epoxy foam‐filled three‐dimensional woven spacer composites (FF‐3DWSC) were prepared, and the behavior of the two composites under bending load was investigated experimentally and numerically. The results show that compared with 3DWSC, FF‐3DWSC displayed a higher bending strength of 134.30 MPa and superior bending stiffness of 9.48 × 106 N·mm2, which was attributed to the synergistic effect of the foam and the skeleton. And unlike the serious damage caused by the significant stress concentration in 3DWSC under bending load, less damage appeared in FF‐3DWSC because the stress was dispersed by the efficient transmission of the load between foam and column yarns. Besides, there was no delamination between the foam and the skeleton after the bending test, indicating the excellent integrated structure of FF‐3DWSC. In addition, the bending behavior of 3DWSC and FF‐3DWSC was simulated on the macro‐scale model by HyperMesh and HyperView. As a result, the finite element analysis results were in close agreement with the experimental results, demonstrating the finite element simulation method proposed here is capable of being used in replacing time‐consuming experiments to study the bending properties of such 3D composites.

Enhanced impact resistance of three‐dimensional woven composites with double‐layer core structure

“…[12][13][14] In recent years, three-dimensional (3D) woven spacer composites with structural integrity and lightweight, robust, and anti-delamination properties have attracted extensive attention. [15][16][17][18] The upper and lower layers of 3DWSC are firmly interweaved together by the vertical pile yarns to form an integrated structure, [19,20] which can effectively prevent the separation of the core and the skin layers. Wang et al [21] compared the compressive property of 3D integral woven spacer composites with different numbers of the interlaced pile yarns.…”

Curved woven lattice truss sandwich panels strengthened by foams: Designing, manufacturing, and testing

“…[17][18][19] Epoxy foam-filled threedimensional woven spacer fiberglass/epoxy composites exhibit higher flexural strength and excellent bending stiffness compared to unfilled. 20 Foam filling can effectively increase the peak load, average load, crushing rate efficiency and overall energy absorption of the structure, but the increase in mass will lead to a decrease in the specific energy absorption. 21 The foam-filled directly improves the compression resistance and provides lateral support for the core pillar and suppresses lateral movement when lateral buckling occurs.…”

“…Foam is characterized by light weight, good energy absorption, and excellent impact resistance 17–19 . Epoxy foam‐filled three‐dimensional woven spacer fiberglass/epoxy composites exhibit higher flexural strength and excellent bending stiffness compared to unfilled 20 . Foam filling can effectively increase the peak load, average load, crushing rate efficiency and overall energy absorption of the structure, but the increase in mass will lead to a decrease in the specific energy absorption 21 .…”

Multi‐walled carbon nanotube grafted 3D spacer multi‐scale composites for electromagnetic interference shielding

“…3D spacer textiles with braided bottom and upper faces and plies establish a distinctive reinforcement material for fiber reinforced polymer composites. [13][14][15] With this fabric architecture, rectangular channels form between the upper and bottom plies, resulting in a compact structural reinforcement with a particular braided cage. 3D spacer glass/epoxy composites can be transformed into conductive lattice structures for efficient EMI shielding by adding the relevant conductive nanoparticle reinforcement.…”