Assessment of damage prediction models for composite laminates under single and repeated low-velocity impacts

The aim is to explore the influence of damage initiation criteria and evolution methods on the damage prediction for composite laminates under single and repeated low-velocity impacts. A 3D finite element model is established to analyze the impact behavior of laminate, and a damage analysis process including the initiation determination, progressive evolution, and constitutive relationship is designed. Hashin criterion based on tensile strain for matrix is modified by an empirical assumption method. Besides, the quantitative evolution of damage area during impact is studied, which provides a new perspective for elucidating the damage mechanism. The numerical model is first validated against the available experimental data. The influence of initiation criteria and evolution methods on damage prediction is then performed in two-phase research. The first phase discusses the prediction capabilities of different combinations under single impact. In the second phase, a method for removing residual vibrations under repeated impacts is proposed. The differences caused by the removal and non-removal of residual vibrations are analyzed, and the sensitivity of these differences to various combinations is discussed. Results show that the numerical prediction agrees well with the experiment in dynamic mechanical response curve. Combining Hashin-Strain criterion with linear equivalent strain method and Puck criterion with exponential equivalent displacement method yields optimal results. Moreover, the sensitivity to differences caused by the residual vibrations effects is related to the initiation criterion, and the evolution method.