Damage mechanics and composite behaviour

A multiscale approach for fatigue life prediction of polymer matrix composite laminates

“…Examples of this class of models can be found in Bergmann and Prinz, 24 Ogin et al, 25 Carswell, 26 and Spearing and Beaumont. 27,28 In addition to the above-mentioned limitations of each of the aforementioned three groups of fatigue models, most of the existing models in the literature heavily depend on experimental parameters which thus makes them too specific and usually applicable to one particular class of Polymer Matrix Composites (PMC's), special type of loading and specific laminate configuration and geometry.…”

“…Progressive damage models are different from residual stiffness/strength models in the sense that they choose a damage variable based on the actual damage mechanism of the composite such as matrix crack, interface failure, fiber fracture, or delaminations; however, similar to the second group, the focus of these models is the study of the damage growth rather than the prediction of the life of the specimen. Examples of this class of models can be found in Bergmann and Prinz, 24 Ogin et al, 25 Carswell, 26 and Spearing and Beaumont. 27,28 In addition to the above-mentioned limitations of each of the aforementioned three groups of fatigue models, most of the existing models in the literature heavily depend on experimental parameters which thus makes them too specific and usually applicable to one particular class of Polymer Matrix Composites (PMC's), special type of loading and specific laminate configuration and geometry.…”

“…Progressive damage models are different from residual stiffness/strength models in the sense that they choose a damage variable based on the actual damage mechanism of the composite such as matrix crack, interface failure, fiber fracture, or delaminations; however, similar to the second group, the focus of these models is the study of the damage growth rather than the prediction of the life of the specimen. Examples of this class of models can be found in Bergmann and Prinz, 24 Ogin et al., 25 Carswell, 26 and Spearing and Beaumont. 27,28…”

Estimation of the Dissipative Heat Sources Related to the Total Energy Input of a CFRP Composite by Using the Second Amplitude Harmonic of the Thermal Signal

“…The fatigue damage in a fibre-reinforced composite can be due to the presence of irregularities of the stress distribution into the material and the presence of mechanisms of damage accumulation that lead to the breakdown of the matrix or fibres or their interfaces [1][2][3][4].…”

“…In general, the composite behaviour during cyclic loading involves three stages of the damage: an initial decrease of the mechanical properties due to the matrix cracking, a stable mechanical degradation growth due to the occurrence of delamination induced by transverse cracks, and a final severe degradation due to the fibres rupture [4][5][6][7][8][9]. These three stages of damage can be assessed by evaluating the material performances in terms of the hysteresis loop changes (rotation and drift) [1,10]. To this purpose, methods that are based on the assessment of Young's modulus [7][8][9] and Poisson's ratio [11] reduction, crack density [12][13][14], and strain density variation [2,15] measurements can be used for describing the material behaviour.…”