Bending deformation limits of corrugated unidirectionally reinforced composites

This paper concerns about deformation limits of circular corrugated unidirectional reinforced composites for bending dominated applications. Hence, a two-dimensional analytical stress function approach is used which takes through-thickness normal stresses into account. Hereby, the possible failure modes, namely fibre fracture and layer delamination, of unidirectional laminated circular corrugated sheets are predicted. Additionally, the accurate representative bending stiffness in corrugated-direction is extracted by using an energy approach. The influence of corrugation geometric parameters on deformation limits and stiffness is experimentally as well as theoretically investigated. For this reason, large curvature validation experiments of four different corrugation types are conducted by means of a specially constructed bending device. Finally, bending charts are provided facilitating the choice of an appropriate corrugation geometry during a preliminary design phase.