Effect of fiber misalignment on bending strength of pultruded hybrid polymer matrix composite rods subjected to bending and tension

It is demonstrated that the unusual failure of unidirectional hybrid carbon and glass fiber composite rods under bending and tension can be explained by a combined experimental, analytical, and numerical analysis. To simulate possible transportation, in-service, and installation conditions, ACCC® conductor cores, manufactured by CTC Global,were tested in three- and four-point bending experiments. Axial stresses were predicted analytically and numerically with the likely failure initiating locations identified for rods subjected to bending with applied axial tension. As expected under pure bending, composite rods will fail catastrophically from excessive compressive stress in the carbon composite region. The initiating damage mechanisms will change from compressive to tensile modes as axial tension increases. Natural fiber misalignment must be considered in the failure analysis of composite rods as it can significantly reduce bending strength and influence the locations of damage initiation.