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Delamination damage is a critical concern for composites-especially for aircraft structures-considering their complex service conditions, which include extreme temperatures and impact threats. This study considers the effect of temperature (À20 C to 110 C) on the mode-I interlaminar failure behavior for unidirectional carbon/epoxy composite laminates, through a series of experiments.A simple double compliances method (DCM) without the measurement of crack length was employed to determine mode I interlaminar fracture toughness, and the accuracy of DCM at different temperatures was validated by comparing the results obtained from DCM with those calculated using ASTM methods. The comparison indicates that fracture toughness values determined from DCM

With the increasing application of composite materials in anti-impact structure, the development of reliable rate-dependent interlaminar constitutive model becomes necessary. This study aims to assess and evaluate the applicability of three types of rate-dependent cohesive models (logarithmic, exponential and power) in numerical delamination simulation, through comparison with dynamic test results of double cantilever beam (DCB) specimens made from T700/MTM28-1 composite laminate. Crack propagation length history profiles are extracted to calibrate the numerical models. Crack propagation contours and fracture toughness data are predicted, extracted and compared to investigate the difference of the three different rate-dependent cohesive models. The variation of cohesive zone length and force profiles with the implemented models is also investigated. The results suggest that the crack propagation length can be better predicted by logarithmic and power models. Although crack propagation length profiles are well predicted, the numerical calculated dynamic fracture toughness tends to be higher than that of experimental measured results. The three models also show differences in the prediction of maximum loading forces. The results of this work provide useful guidance for the development of more efficient cohesive models and more reliable interface failure simulation of impact problems.