A Fracture Mechanics Approach to Interlaminar Failure of Unidirectionally Reinforced Composites

Abstract

Models are proposed for initiation and completion of failure in unidirectionally reinforced composites under longitudinal shear. The models allow characterization of the effect of fiber volume content on the average shear strength of composites considered as homogeneous material. Results are compared with experiments.

Parametric Damage Modelling of Composites Due to Moisture Absorption

“…Often, the strength between the fiber and the matrix (resistance to debonding) is considered as an independent parameter [2,4] which depends on the properties of the interlaminar phase. This is especially true when (1) the adhesion strength between the fiber and the matrix is deliberately reduced in order to increase the toughness of the composite; (2) a separate thin layer of interface material of low modulus is introduced to reduce the stress concentration; (3) a separate layer is used for the adhesion.…”

“…The role of interfacial shear strength has been emphasized by some researchers including the work of G. C. Shih and L. J. Ebert [9] for modelling the longitudinal tensile strength of composites. For simplicity, it is here assumed that the bonding material fails when the shear stress in it exceeds a critical value &dquo;T6 Further, it is assumed that this allowable stress decreases linearly with moisture content M, as expressed by Equation (4).…”

“…And that the composite failure occurs when the moisture weakens the bonding phase material to render it unable to hold together the matrix and the reinforcement. Now the damage of the bond material is a problem both in surface chemistry and fracture mechanics [3][4][5]. It is extremely difficult to predict when this material will fail.…”

Study on Constitutive Model and Failure Criterion of Cord-Rubber Composite

“…Cord-rubber composite has been studied for a long time. However, theories on its failure prediction have not been perfected [12][13][14][15] and are mainly involved in the study of its fatigue [16,17]. Failure criteria of traditional composite are often taken to predict the failure of cordrubber composite [18][19][20].…”