Accurate Stress Analysis of Variable Angle Tow Shells by High-Order Equivalent-Single-Layer and Layer-Wise Finite Element Models

Abstract

New concepts of lightweight components are conceived nowadays thanks to the advances in the manufacture of composite structures. For instance, mature technologies such as Automatic Fibre Placement (AFP) are employed in the fabrication of structural parts where fibres are steered along curvilinear paths, namely variable angle tow (VAT), which can enhance the mechanical performance and alleviate the structural weight. This is of utmost importance in the aerospace field, where weight savings are one of the main goals. For that reason, shell structures are commonly found in the aerospace industry because of their capabilities of supporting external loadings. Straight-fibre composite shell structures have been studied in recent decades and, now, spatially varying composite shells are attracting the attention of manufacturers. This work analyses the mechanical behaviour of VAT composite shells subjected to different external loadings and boundary conditions. The Carrera Unified Formulation (CUF) is employed to obtain the different structural models in a systematic and hierarchic manner. The outcomes of such numerical models are discussed and compared with commercial software Abaqus.

A FEM Free Vibration Analysis of Variable Stiffness Composite Plates through Hierarchical Modeling

“…In Viglietti et al [ 27 ] and Fallahi et al [ 28 ], free vibration and buckling analyses of VATs were performed through the use of a 1D CUF model. Within this framework, shell models were developed as well for VAT cases in order to perform stress analyses; see Sánchez-Majano et al [ 29 ]. In Pagani and Sánchez-Majano [ 30 , 31 ] and Sánchez-Majano et al [ 32 ], manufacturing defects were taken into account by using stochastic techniques.…”

Buckling and post-buckling of variable stiffness plates with cutouts by a single-domain Ritz method

“…Starting from the pioneering works of Hyer and coworkers [5,6], many studies have been performed in the literature by using the finite element method (FEM), see e.g. [7,8,9,10,11,12,13], only to cite some recent works, that largely contributed to the understanding of variable stiffness composites behaviour as regard stress distributions, buckling, vibrations and failure.Starting from the pioneering works of Hyer and coworkers [5,6], many studies have been performed in the literature by using the finite element method (FEM), see e.g. [7,8,9], only to cite some recent works, that largely contributed to the understanding of variable stiffness composites behaviour.…”

Analysis of the manufacturing signature on AFP-manufactures variable stiffness composite panels

“…CUF permits obtaining the governing equations of any structural theory without making ad hoc assumptions. So far, CUF has proven to predict accurate stress states [5], as well as capture the influence of multiscale uncertainty defects on the mechanical performance of VAT plates [6].…”