Three-dimensionally woven glass fiber composite struts: characterization and mechanical response in tension and compression

Abstract

Three-dimensionally woven E- and S2-glass fiber textiles have been used in the past to create delamination-resistant corrugated core sandwich panels. During subsequent out-of-plane loading, the E-glass composite core struts and S2-glass composite faces are subjected to either compressive or tension loads. This study has investigated the relationships between the three-dimensional fiber architecture, fiber properties and the mechanical response of representative samples of the core and faces. Using X-ray computed tomography and optical microscopy to characterize the three-dimensional fiber architectures, it is found that the in-plane warp and weft fibers suffer significant off-axis displacement (waviness) due to their interaction with through thickness z-fiber tows. The consequence of this fiber waviness on the relationships of the in-plane tensile and compressive mechanical properties, along with fiber type, fiber volume fraction, and strut aspect ratio are experimentally investigated. The large initial misalignment angle of the warp and weft fiber tows results in a strut compressive strength that is substantially lower than its tensile strength due to compressive failure by either elastic or localized fiber microbuckling. Simple micromechanical models are used to relate the compressive strength of the three-dimensional woven composite struts to strut aspect ratio, fiber volume fractions in the three directions and the three-dimensional fiber architecture.

Honeytubes: Hollow lattice truss reinforced honeycombs for crushing protection

“…Additionally, lattice composites, which are hybrids of lattice structures and fiber composites, can yield superior specific properties and populate vacant spaces in low-density regions of materials property charts [19][20][21][22][23][24]. Recent efforts have focused on fabrication techniques for these lattice composites, including interlocking [25], weaving [26], and hot press molding [27,28], although low-cost and large-volume approaches are still required to bring such structures into use.…”

Sandwich Structures with Prismatic and Foam Cores: A Review

“…The combination of Kevlar stitching of a corrugated E‐glass core to face sheets made of a high strength S2‐glass fiber, along with the large contact area between the core webs and the face sheets, resulted in a robust core‐face sheet attachment with high load transfer capacity. The technique was then used to fabricate a variety of corrugated core sandwich structures . Kazemahvazi et al compared the quasi‐static and dynamic mechanical performance of 3D‐assembled (integrated woven), CFRP, and 6061‐T6 beams by three‐point‐bending and impact.…”

Shear response of carbon fiber composite octet-truss lattice structures

“…Experimental [11,12,15] and more fundamental studies [37,38,39,40] have shown that the compressive strengths of woven laminates are lower than unidirectional laminates due to fiber waviness. It is noted that the as-received laminate sheets contained two plain weave fabrics, four 0º unidirectional plies and two 90º unidirectional plies.…”

“…The mechanical performance of a sandwich panel is governed by its geometry (face sheet thickness and core height) and by the mechanical properties of its faces and core with the latter governed by the core topology and properties of the materials used to make it. In addition to their significant bend resistance, some sandwich panel structures also provide substantial out of plane compressive strength [7,8,9,10,11,12,13,14,15], and have attracted interest for mitigating the effects of impulsively applied loads [16,17,18,19,20,21].…”