Modelling of the transverse strength of fibre reinforced epoxy composite at low and high temperature

Process-induced thermal residual stresses and matrix failure of unidirectional carbon fibre reinforced composites (CFRP) have been investigated by finite element analysis (FEA). We used a partial discrete FEA model based on a unidirectional composite consisting of a microscopic area of fibres and matrix surrounded by a homogenised composite area. The FEA provided information about the stress state in the matrix and the fibre-matrix interface. The transverse strength of the composite was calculated regarding matrix failure and fibre matrix debonding. The influence of the temperature on the Young's modulus, the non-linear stress-strain behaviour and the strength of the matrix were investigated in detail. Following this approach it was possible to incorporate the resulting micro-residual stresses on the transverse strength of the composite. Tensile tests of the neat resin and of the composite were performed in the temperature range of -40 °C to 60 °C. The results of the FEA modelling are in good agreement with the experimental results of the transverse tests. © VSP 2005.

Subjects

Carbon fibre

Debonding

Finite element analysis (FEA)

Matrix cracking

Residual stress

Transverse failure

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Modelling of the transverse strength of fibre reinforced epoxy composite at low and high temperature