Effects of corrugation on the stiffness properties of composite beams for structural applications

The primary goal of this research was to investigate the stiffness characteristics of trapezoidal corrugated composite laminates under tensile and flexural load. Stiffness was calculated experimentally, analytically, and numerically in two directions. The longitudinal direction was defined as perpendicular to the corrugations and transverse direction along the corrugations. The stiffness ratio is the ratio of longitudinal stiffness to transverse stiffness. The effects of corrugations were measured by comparing changes to the stiffness ratios of flat and corrugated composite beams in tension and bending. For corrugated fibreglass coupons, the extensional stiffness ratio was increased from 1.0 to 49 and the flexural stiffness ratio was increased from 0.3 to 187. For carbon fibre coupons, the extensional stiffness ratio increased from 0.7 to 61.3 and the flexural stiffness ratio increased from 0.3 to 81.4. Corrugation of composite beams has shown a significant increase in stiffness for tensile and bending applications.