Spiral and helical fractures

Spiral and helical fractures can be formed around high‐modulus filaments and yarns which are embedded in brittle, amorphous, crosslinked resins. The phenomena are of particular interest because the stress field imposes a highly regular geometry upon the propagating fractures, and because the formation of the large surface area of the spiral fractures provides an efficient mechanism for dissipating strain energy. Development of the approach of the production of discrete geometrical voids with large surface area at predicatable sites may well provide resistance to impact in inherently brittle materials.