Efficient modelling of delamination buckling in composite cylindrical shells under axial compression

Abstract

Composite cylindrical shells and panels are widely used in aerospace structures. These are often subjected to defects and damage from both in-service and manufacturing events.Delamination is the most important of these defects. This paper deals with the computational modelling of delamination in isotropic and laminated composite cylindrical shells. The use of three-dimensional finite elements for predicting the delamination buckling of these structures is computationally expensive. Here combined double-layer and single-layer of shell elements are employed to study the effect of delamination on the global load-carrying capacity of such systems under axial compressive load. It is shown that through-the-thickness delamination can be modelled and analysed effectively without requiring a great deal of computing time and memory. A parametric study is carried out to study the influence of the delamination size, orientation and through-the-width position of a series of laminated cylinders. The effect of material properties is also investigated. Some of the results are compared with the corresponding analytical results. It is shown that ignoring the contact between the delaminated layers can result in wrong estimations of the critical buckling loads in cylindrical shells under compressive load.

Optimum Shape Design of Composite Structures Using Boundary-Element Method.

“…Four different materials [16,17] are used to investigate the effect of engineering constants on the optimum shape design of the components. Every component is being treated as a lamina that has four engineering constants E 1 , E 2 , G 12 and  12 with a lamina orientation angle of zero.…”

Fracture Mechanics Analysis of Composite Structures Using the Boundary Element Shape Sensitivities

“…The study on instability analysis of delaminated composite cylindrical shells subject to axial compression, external pressure and bending, either applied individually or in combination [21][22][23] showed that the SERR was more convenient to be used for the prediction of crack growth and fracture of delaminated composite structures. Here it is shown that although the SIF is of fundamental importance in the prediction of brittle failure using linear elastic fracture mechanics, the SERR for cracked anisotropic meshes has been found to be more convenient for these predictions.…”

Delamination buckling and postbuckling in composite cylindrical shells under combined axial compression and external pressure

“…The presence of delaminations leads to a reduction in the overall buckling strength of the structure [3][4]. For the past two decades analytical and numerical analyses have been carried out by many researchers to analyse delaminated composite structures, considering their buckling and post-buckling behaviour [5][6].…”

“…[17][18][19][20][21][22][23]. Due to its mathematical complexity and modelling, very limited information on the subject of delamination buckling of cylindrical shells and panels is currently available [3][4][24][25][26][27][28][29][30][31][32][33]. The most comprehensive analytical study is by Simitses et al [25][26][27].…”

“…In the recent numerical studies [3][4] by the author, delamination buckling and postbuckling of composite cylindrical shells under axial compression [3] and external pressure [4], applied individually, were considered. For both loading cases, the effect of contact between the delaminated layers was taken into account.…”