Three-dimensional colour functions for stress state visualisation

Three-dimensional colour functions were designed for visually agreeable and computationally efficient stress state visualisation in failure analysis. The colours they generate depend on three aspects of the stress state: the distance to failure, the stress character (compressive or tensile), and the relative magnitude of the intermediate principal stress. Thus, the colour of a single pixel carries information about all three scalar components of the stress tensor at a point. By discarding the intermediate principal stress information, a three-dimensional colour function degenerates to a family of two-dimensional colour functions with free palette choice parameter. We demonstrate the performance of our colouring technique in the application example – visualisation of the stress field in the Brazilian test.