The role of shear deformation in laminated plates with curvilinear fiber paths and embedded defects

Automated Fiber Placement (AFP) is an advanced technology used to manufacture laminated composites with curvilinear fiber paths. During the manufacturing, AFP generally leads to the formation of defects, e.g. gaps and overlaps, that impact the laminate properties, to an extent that largely depends on the geometry, such as thickness and curvature, of the part. This paper focuses on moderately-thick laminate plates that present gaps and overlaps induced by AFP. We use higher-order shear deformation theories to study the role of shear deformation on the plate responses. A hybrid Fourier-Galerkin method is used to obtain a semi-analytic solution describing the static deformation of the plate. Eigenvalue analysis is also conducted to determine its fundamental frequency and critical buckling load. The numeric results show that shear deformation has a more severe impact on the structural responses of a variable stiffness than a constant stiffness plate. We find also that gaps deteriorate the structural performance, while overlaps improve it. Maps representing structural responses, in particular buckling vs. deflection and frequency vs. deflection, are generated to gain insight into the design of a variable stiffness laminate plate with defects.