A Study of Failure Strength for Fiber-Reinforced Composite Laminates with Consideration of Interface

Abstract EN

Composite laminates can exhibit the nonlinear properties due to the fiber/matrix interface debonding and matrix plastic deformation.

In this paper, by incorporating the interface stress-displacement relations between fibers and matrix, as well as the viscoplastic constitutive model for describing plastic behaviors of matrix materials, a micromechanical model is used to investigate the failure strength of the composites with imperfect interface bonding.

Meanwhile, the classic laminate theory, which provides the relation between micro- and macroscale responses for composite laminates, is employed.

Theory results show good consistency with the experimental data under unidirectional tensile conditions at both 23°C and 650°C.

On this basis, the interface debonding influences on the failure strength of the [0/90]s and [0/±45/90]s composite laminates are studied.

The numerical results show that all of the unidirectional (UD) laminates with imperfect interface bonding provide a sharp decrease in failure strength in the σxx-σyy plane at 23°C.

However, the decreasing is restricted in some specific region.

In addition, for [0/90]s and [0/±45/90]s composite laminates, the debonding interface influences on the failure envelope can be ignored when the working temperature is increased to 650°C.