Non-uniform and dynamic torsion of elastic beams Part 2: the double torsion test

Part 1 of this paper developed a one-dimensional fourth-order partial diffe rential equation for dynamical torsion of rectangular beams. It was then va lidated against static and dynamic test cases. This concluding part applies the equation to the double torsion fracture test, in which a crack propaga tes along the plane joining two adjacent torsion beams as they are twisted in opposite senses. The resulting model is extensively validated against ex perimental and finite element results. It is then used to explain the shape of the curved crack front which is characteristic of this test.