Investigation into the changes in bending stiffness of a textile reinforced composite due to in-plane fabric shear: Part 1 – Experiment

Abstract

A study to investigate the factors that contribute to the variation among the stiffnesses of consolidated composite plates reinforced by plain-weave fabrics with various degrees of in-plane shear is presented. The first part of the two-part study focuses on the experiments performed. Threepoint bend tests were used to measure the effective stiffness of the composite plates along the global X and Y axes, which were aligned with the weft and warp orientations, respectively, in the undeformed configuration at 0° of shear. The warp yarns were sheared 0°, 10°, 20°, 25° and 30° toward the weft yarns. It was observed that as the shear angle in the plates increased, the thickness of the plates also increased. An increase in stiffness for bending in X-direction with increasing shear angle was observed as was expected, but the change in stiffness for bending in Y-direction was observed to be inconsistent with the expected decrease with increasing degree of shear.

Investigation into the changes in bending stiffness of a textile reinforced composite due to in-plane fabric shear: Part 2 – Numerical analysis

“…All of the plates in the current study were reinforced by a single-ply of a plain-weave fabric [38]. Three-point-bend tests performed on the plates resulted in similar curvatures for equivalent positive and negative moments, confirming symmetry of the specimens about the neutral surface.…”

“…Part 1 of this investigation [38] described the manufacture of composite plates reinforced by textiles with various degrees of in-plane shear. The current work will refer to two coordinate systems defined by the plates' geometries, as depicted in Fig.…”

“…The load-displacement curves for flexure tests performed in Part 1 of the analysis [38] are depicted in Fig. 3(a) and Fig.…”

“…In Part 1, the effects of in-plane shear on the flexural behavior of textile-reinforced composite plates were examined using an experimental approach, and the manufacture of the plates with various degrees of in-plane shear within the textile reinforcement was discussed in detail [38]. In Part 2, the respective significances of the geometric changes within the plates caused by the shearing of the fabric reinforcements are investigated using a numerical approach.…”

A Study on the Initial Fracture Behavior of CF/GF Intra-Hybrid Woven Fabric Reinforced Composites

“…Kim, D. H., Kim, H. G. and Kim, H. S [27] designed and manufactured hybrid glass/carbon composite bumper beam was via the design optimization process combined with the impact analysis. In the study of Cynthia Mitchell, Lisa Dangora, Christie Bielmeier and James Sherwood [28], investigations were pursued in an effort to understand the relationship between changes in the stiffness of plain-weave fabric-reinforced plates and the degree of in-plane shear within the fabric reinforcement. They identified that fabric shearing will result in several major changes within the reinforcement geometry that the reorientation of the fibers within the plane of the plate, the increase in plate thickness with increasing shear angle, and the change in the tow cross-sectional shape and orientation.…”