Analysis of damage localization in composite laminates using a discrete damage model

Abstract

Damage localization around stress raisers and material defects in laminated composites is studied using a discrete damage mechanics model augmented by a fiber damage model. The proposed formulation captures the damaging behavior of plates with initial defects and stress raisers such as holes, including damage initiation, evolution, and ultimate fracture of the specimen. It also helps explain the reduction of stress concentration factor when matrix and fiber damage develop. The state variables are the crack density and the fiber failure damage. The formulation is implemented as a material model in Abaqus applicable to laminated composite plates and shells. Material defects are simulated by inserting an initial crack density in a small region of the specimen. Stress raisers are simulated by an open hole. The predictions are shown to be insensitive to mesh density. Further, damage localizes near stress raiser and material defects, thus numerically demonstrating the objectivity of the proposed model. Qualitative and quantitative comparisons with experimental data are presented.

Micro/macro approach for prediction of matrix cracking evolution in laminated composites

“…Using this approach it is possible to perform damage analyses for laminates containing discontinuities 22 . Synergistic damage mechanics merging crack opening displacement (COD) method and CDM is presented in 23,24 .…”

Damage evolution in open-hole laminated composite plates subjected to in-plane loads

“…The method has been extended to include fibre failure [22]. The fibre failure is incorporated to the method through a simple fibre damage model that only requires one additional material property.…”

“…In this work, a Regula Falsi method is proposed to achieve convergence for plies crack density. The original DDM described in [20] does not take into account fibre failure; therefore a short description of the fibre damage model presented in [22] is done first. 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 The second part of this section presents the DDM formulation considering fibre damage.…”

“…The model is formulated on a representative volume element (RVE), which is chosen as the volume enclosed by the mid-surface and top-surface of the laminate, the surfaces between two consecutive cracks 2l, and a unit length along the fibre direction parallel to the cracks [22].…”

Numerical Simulation on Damage Mode Evolution in Composite Laminate

“…Other types of studies use the finite element method [8]. We can also find some models based on phenomenological approaches [9], self-consistent analyses [10] or approaches based on specific aspects of the cracks [11][12][13][14]. The longitudinal cracking is equivalent to transverse cracking damage, but arise in the longitudinal plies (0° layers).…”