On the reliability of residual stress measurements in unidirectional carbon fibre reinforced epoxy composites

The present work introduces a novel methodology to analyse non-uniform residual stresses in composite materials. For robust determination of complex structures made different layers, it is first necessary prove that stress analysis single layer structure can reliably be accomplished. In unidirectional carbon fibre reinforced epoxy investigated. determination, the integral incremental hole drilling method used. It revealed standard evaluation formalism for isotropic not applicable. A based on uniform orthotropic materials introduced and applied determining states depth. calibration, known load induced by bending samples. By comparing data obtained with stresses, reliability measurements analysed validated.