Modeling Damage Propagation in Composite Plates with Embedded Delamination under Compressive Load

Abstract

A numerical procedure aimed at simulating the structural behavior of delaminated composite plates under compressive load, is developed and presented in this article. Although delamination buckling and growth have been widely studied in the literature, in this article the effect of fiber—matrix failure on the buckling behavior of a delaminated structure up to final failure is investigated in detail. A geometrically non linear finite element (FE) approach is adopted for elastic instability simulation, the modified virtual crack closure technique (MVCCT) is used for the energy release rate (ERR) evaluation at the delamination front and fracture mechanics based progressive damage approach is introduced for the simulation of fiber—matrix damage onset and evolution. Comparisons of numerical results with existing experimental data on composite panels with an embedded circular delamination under compressive load, are presented for preliminary validation purposes. Furthermore, the influence of the different failure mechanisms on the compressive behavior of delaminated composite plates is assessed, by comparing numerical results obtained with models characterized by different degrees of complexity. Finally, results of a limited sensitivity analysis are shown, pointing out the influence of some key parameters characteristics of the adopted numerical approach on the accuracy of numerical simulations.

Progressive Failure Analysis of Composite Structures Using a Constitutive Material Model (USERMAT) Developed and Implemented in ANSYS ©

“…An extensive and expensive material characterization is required that in most cases is not feasible. Thus, progressive failure techniques still represent a valuable alternative either when the objective is to design damage tolerant structure or to evaluate the residual strength of a composite structure [20][21][22][23][24]. The aim of this paper is to analyse the behaviour of a composite structures subjected to static loads taking into account onset and progression of damage.…”

A Global/Local Finite Element Approach for Predicting Interlaminar and Intralaminar Damage Evolution in Composite Stiffened Panels Under Compressive Load

“…A great amount of literature works have been devoted to the analysis of the postbuckling behaviour of structures with embedded delamination [2][3][4][5][6][7][8] but only in a few cases the presence of intralaminar damage has been considered too [9][10][11][12].…”

“…[9,10] or by releasing not merged nodes laying in the same position (i.e. having the same coordinates) but belonging to two different fracture surfaces [5,11,12,16].…”

“…A widely used approach, for the simulation of the behaviour of composite structures beyond the detection of the first ply failure, consists in the change of the material properties for failed elements according to suitable degradation rules (ply discount approach) [19]. This approach has been extensively used for the analysis of composite plates with holes [19][20][21][22][23][24][25][26][27] but only in a few cases it has been applied to the analysis of delaminated plates [10,12].…”

“…Within this work a numerical procedure is adopted [12], based on the combined use of the Virtual Crack Closure Technique and of a ply discount approach. The occurrence of matrix cracks, fibre breakages and all the others intralaminar failures are verified (see Table 1) for each ply of the laminate at each load step of a non linear incremental analysis.…”