Assessment of free-edge singularities in composite laminates using higher-order plate elements

Abstract

International audienceThe capabilities and limitations of refined two-dimensional (2D) composite plate elements are discussed with respect to the stress concentration problem occurring at traction-free edges. Classical displacement-based and advanced partially mixed finite elements are formulated according to Carrera’s Unified Formulation (CUF). Rectangular laminates are analyzed under extension and bending loading, where the attention is focused on the local stress response at the free edges. Present results are compared with reference results available in the literature and a 3D finite element model. A power law representation for a singular stress field is used to fit the obtained stresses in the vicinity of the free edge, and the parameters are used to assess the CUF elements and to compare the free-edge effect occurring in extension and bending

Progressive Damage in thin 2D Woven CFRP Laminates due to Stress Concentrations at Free Edges and Notches

“…Furthermore, Carrera et al [21] developed a numerical model based on a high-order beam theory, with which the stress field at free edges in generic laminated composites can be described. Apart from three-dimensional FEM, investigations were carried out to determine whether two-dimensional approaches are appropriate [22,23,24]. The investigations quoted in advance were concerned with unidirectional angle-ply and cross-ply laminates.…”

Progressive Damage in thin 2D Woven CFRP Laminates due to Stress Concentrations at Free Edges and Notches

“…Furthermore, Carrera et al [21] developed a numerical model based on a high-order beam theory, with which the stress field at free edges in generic laminated composites can be described. Apart from three-dimensional FEM, investigations were carried out to determine whether two-dimensional approaches are appropriate [22,23,24]. The investigations quoted in advance were concerned with unidirectional angle-ply and cross-ply laminates.…”

A new robust quadrilateral four-node variable kinematics plate element for composite structures

“…Within CUF, classical displacement-based plate elements are defined through the choice of i() the description at laminate level (ESL or LW), (ii) whether a Zig-Zag function is to be used or not, and (iii) the order N of the polynomial expansion assumed for the displacement field. The original version of CUF as presented by [24] has been implemented as Abaqus User Element with a dedicated Python-based preprocessing tool [25]; this package has been successfully employed in, e.g., [26,27] and forms the basis of the developments proposed in this paper.…”