Assessment of damage prediction models for composite laminates under low-velocity impact

For the prediction of low-velocity impact damage in carbon fiber composite laminates, this study examined the influence of three damage initiation criteria and three evolution methods from structural overall mechanical response and internal damage state. To facilitate our investigation, a three-dimensional finite element model analyzing the impact behavior of laminate was established. Subsequently, a damage calculation process encompassing initiation determination, progressive evolution, and constitutive relationship was designed. Additionally, the quantitative evolution of damage area during impact was studied, which provided a new perspective for elucidating the damage mechanism. Based on experimental data, the accuracy of numerical simulation was verified. Then the prediction capabilities of different initiation criteria and evolution methods were evaluated and discussed. The results show that the numerical prediction agrees well with the experiment in dynamic mechanical response curve. This proves the numerical model can accurately predict the impact damage. Meanwhile, it has been found that the combination of initiation criteria and evolution methods significantly impacts the predictive efficacy of damage models. The pairing of the Hashin-Strain criterion with the linear equivalent strain method (Hashin-strain-E1) and the Puck criterion with the exponential equivalent displacement method (Puck-E3) yields optimal results. However, coupling the Hashin-Strain criterion with either the linear or exponential equivalent displacement method (Hashin-strain-E2/E3) can lead to penetrating damage due to severe degradation in stiffness. These research findings offer valuable insights into predicting low-velocity impact damage in composite laminates.