Post Buckling Progressive Failure Analysis of Composite Laminated Stiffened Panels

Abstract

The present work deals with the numerical prediction of the post buckling progressive and final failure response of stiffened composite panels based on structural nonlinear finite element methods. For this purpose, a progressive failure model (PFM) is developed and applied to predict the behaviour of an experimentally tested blade-stiffened panel found in the literature. Failure initiation and propagation is calculated, owing to the accumulation of the intralaminar failure modes induced in fibre reinforced composite materials. Hashin failure criteria have been employed in order to address the fiber and matrix failure modes in compression and tension. On the other hand, the Tsai-Wu failure criterion has been utilized for addressing shear failure. Failure detection is followed with the introduction of corresponding material degradation rules depending on the individual failure mechanisms. Failure initiation and failure propagation as well as the post buckling ultimate attained load have been numerically evaluated. Final failure behaviour of the simulated stiffened panel is due to sudden global failure, as concluded from comparisons between numerical and experimental results being in good agreement.

Stiffness degradation of composite skin fields due to strength and buckling onset

“…Prediction of failure onset and propagation can be done utilizing the finite element method (FEM) (e.g. see Oh et al [32], Daghia and Ladevèze [19], Adden and Horst [1], Anyfantis and Tsouvalis [3]). Compared to the closed form solutions, the FEM more accurately computes the material behaviour after failure onset, e.g.…”

Nonlinear Analysis of Fiber-Reinforced Composite Laminates Subjected to Uniaxial Compressive Load

“…Hence, it has the similar trend as the Chang criterion . When o o 15 80 ,    the predicted transverse stress 2  by the Rotem criterion is lower than that by mixed criterion and the predicted in-plane shear stress 12  by the Rotem criterion is higher than that by mixed criterion (Fig. 19b).…”

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

“…The transformation of the stiffness in the global coordinate system, according to the laminate staking sequence defined for each element (as SECTION [26]), is performed automatically by ANSYS outside of the usermat. Often progressive failure procedures have been implemented as post-processing routines especially when using ANSYS [20][21][22]. This is principally because it is quite easy to implement post-processing routines in ANSYS by means of the Parametric Design Language (APDL), which allows stopping and restarting analyses, storing data as matrices and obtaining directly data from the model and from the result file.…”

“…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.…”