Sub-critical crack growth in highly stressed Formula 1 race car composite suspension components

One of the many advantages in the use of composite materials in engineering structures is their resistance to fatigue. Careful component design means that complex, weight-efficient components can be produced which are “intrinsically safe” in that they have an effectively infinite fatigue life. Excessive loading and manufacturing/design details may, however, invoke a process analogous to fatigue in metal components leading to ultimate failure of the component at a load below its design limit. A somewhat qualitative analysis has shown this mechanism to result primarily due to sub-critical crack growth within the resin matrix material. Although the phenomena need further investigation, it was found that the crack growth could be suppressed by using a resin matrix with a much higher toughness. A short introduction to the use of composite materials in Formula 1 is provided along with a discussion to illustrate how the practical application of Materials Science and Fracture Mechanics principles were used to solve a potentially serious problem.