A new strength model for application of a physically based failure criterion to orthogonal 3D fiber reinforced plastics

A strength model for 3D fiber-reinforced plastics consisting of unidirectional layers with a high in-plane fiber density and additional reinforcements perpendicular to the layers with a significantly lower fiber density is presented. The strength model aims to enhance the application range of an existing, physically based failure criterion for inter-fiber fracture of unidirectional fiber-reinforced layers to the above mentioned configuration of 3D-composites. In doing so the fundamental physical basis, the fracture hypothesis of Mohr, and the general mathematical formulation of the criterion are sustained. The enhancement of the application range is achieved by employing a continuous interpolation between the basic strengths of an orthogonal 3D fiber-reinforced layer.